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19-0622; Rev 0; 8/06
Dual-/Triple-/Quad-Voltage, CapacitorAdjustable, Sequencing/Supervisory Circuits
General Description
The MAX16041/MAX16042/MAX16043 are dual-/triple-/ quad-voltage monitors and sequencers that are offered in a small thin QFN package. These devices offer enormous design flexibility as they allow fixed and adjustable thresholds to be selected through logic inputs and provide sequence timing through small external capacitors. These versatile devices are ideal for use in a wide variety of multivoltage applications. As the voltage at each monitored input exceeds its respective threshold, its corresponding output goes high after a propagation delay or a capacitor-set time delay. When a voltage falls below its threshold, its respective output goes low after a propagation delay. Each detector circuit also includes its own enable input, allowing the power-good outputs to be shut off independently. The independent output for each detector has an open-drain configuration capable of supporting voltages up to 28V, thereby allowing them to interface to shutdown and enable inputs of various DC-DC regulators. Each detector can operate independently as four separate supervisory circuits or can be daisy-chained to provide controlled power-supply sequencing. The MAX16041/MAX16042/MAX16043 also include a push-pull reset function that deasserts only after all of the independently monitored voltages exceed their threshold. The reset timeout is internally fixed or can be adjusted externally. These devices are offered in a 4mm x 4mm TQFN package and are fully specified from -40C to +125C.
Features
o 2.2V to 28V Operating Voltage Range o Fixed Thresholds for 3.3V, 2.5V, 1.8V, 1.5V, and 1.2V Systems o 1.5% Accurate Adjustable Threshold Monitors Voltages Down to 0.5V o 2.7% Accurate Fixed Thresholds Over Temperature o Fixed (140ms min)/Capacitor-Adjustable Delay Timing o Independent Open-Drain Outputs/Push-Pull RESET Output o Enable Inputs for Each Monitored Voltage o 9 Logic-Selectable Threshold Options o Manual Reset and Tolerance Select (5%/10%) Inputs o Small, 4mm x 4mm TQFN Package o Fully Specified from -40C to +125C
MAX16041/MAX16042/MAX16043
Ordering Information
PART* MAX16041TE+ MAX16042TP+ MAX16043TG+ TEMP RANGE -40C to +125C -40C to +125C -40C to +125C PINPACKAGE 16 TQFN 20 TQFN 24 TQFN PKG CODE T1644-4 T2044-3 T2444-4
+Denotes lead-free package. *For tape and reel, add a "T" after the "+." All tape and reel orders are available in 2.5k increments.
Applications
RESET OUT1
Pin Configurations
OUT3 TH0 13 12 11 10 TH1 EN4 EN3 EN2 EN1 GND 9 8 7 1 VCC 2 IN1 3 IN2 4 IN3 5 IN4 6 TOL
DC-DC Supplies Servers/Workstations Storage Systems Networking/Telecommunication Equipment
TOP VIEW
18 MR 19 CRESET 20 CDLY4 21
17
16
OUT2
15
14
Selector Guide
PART MAX16041 MAX16042 MAX16043 MONITORED VOLTAGES 2 3 4 INDEPENDENT OUTPUTS 2 (Open-drain) 3 (Open-drain) 4 (Open-drain) RESET OUTPUT Push-pull Push-pull Push-pull
CDLY3 22 CDLY2 23 CDLY1 24
MAX16043
+
TQFN (4mm x 4mm)
Pin Configurations continued at end of data sheet.
________________________________________________________________ Maxim Integrated Products 1
For pricing, delivery, and ordering information, please contact Maxim/Dallas Direct! at 1-888-629-4642, or visit Maxim's website at www.maxim-ic.com.
OUT4
Multivoltage Systems
Dual-/Triple-/Quad-Voltage, CapacitorAdjustable, Sequencing/Supervisory Circuits MAX16041/MAX16042/MAX16043
ABSOLUTE MAXIMUM RATINGS
(All voltages referenced to GND.) VCC .........................................................................-0.3V to +30V EN1-EN4 ....................................................-0.3V to (VCC + 0.3V) OUT1-OUT4 ...........................................................-0.3V to +30V RESET.........................................................-0.3V to (VCC + 0.3V) IN1-IN4.......................................................-0.3V to (VCC + 0.3V) MR, TOL, TH1, TH0 ....................................-0.3V to (VCC + 0.3V) CDLY1-CDLY4 .........................................................-0.3V to +6V CRESET ......................................................-0.3V to (VCC + 0.3V) Input/Output Current (all pins)..........................................20mA Continuous Power Dissipation (TA = +70C) 16-Pin TQFN (derate 25mW/C above +70C) ...........2000mW 20-Pin TQFN (derate 25.6mW/C above +70C) ........2051mW 24-Pin TQFN (derate 27.8mW/C above +70C) ........2222mW Operating Temperature Range .........................-40C to +125C Storage Temperature Range .............................-65C to +150C Junction Temperature ......................................................+150C Lead Temperature (soldering, 10s) .................................+300C
Stresses beyond those listed under "Absolute Maximum Ratings" may cause permanent damage to the device. These are stress ratings only, and functional operation of the device at these or any other conditions beyond those indicated in the operational sections of the specifications is not implied. Exposure to absolute maximum rating conditions for extended periods may affect device reliability.
ELECTRICAL CHARACTERISTICS
(VCC = 2.2V to 28V, TA = -40C to +125C, unless otherwise specified. Typical values are at VCC = 3.3V and TA = +25C.) (Note 1)
PARAMETER SUPPLY Operating Voltage Range Undervoltage Lockout Undervoltage-Lockout Hysteresis VCC UVLO (Note 2) (Note 2) 2.2 1.8 1.9 50 VCC = 3.3V VCC = 12V VCC = 28V 2.970 2.805 2.250 2.125 1.620 1.530 1.350 1.275 1.080 1.020 0.492 0.463 500 -100 40 47 52 3.052 2.888 2.313 2.187 1.665 1.575 1.387 1.312 1.110 1.050 0.5 0.472 0.5 Fixed threshold IL Adjustable threshold only (VIN_ = 1V) 918 +100 75 75 80 3.135 2.970 2.375 2.250 1.710 1.620 1.425 1.350 1.140 1.080 0.508 0.481 V % k nA V A 28.0 2.0 V V mV SYMBOL CONDITIONS MIN TYP MAX UNITS
UVLOHYST VCC falling All OUT_ and RESET at logic-high (IN_ current excluded)
VCC Supply Current INPUTS (IN_)
ICC
3.3V threshold, TOL = GND 3.3V threshold, TOL = VCC 2.5V threshold, TOL = GND 2.5V threshold, TOL = VCC IN_ Thresholds (IN_ Falling) VTH 1.8V threshold, TOL = GND 1.8V threshold, TOL = VCC 1.5V threshold, TOL = GND 1.5V threshold, TOL = VCC 1.2V threshold, TOL = GND 1.2V threshold, TOL = VCC Adjustable Threshold (IN_ Falling) IN_ Hysteresis (IN_ Rising) IN_ Input Resistance IN_ Input Current VTH VHYST TOL = GND TOL = VCC
2
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Dual-/Triple-/Quad-Voltage, CapacitorAdjustable, Sequencing/Supervisory Circuits
ELECTRICAL CHARACTERISTICS (continued)
(VCC = 2.2V to 28V, TA = -40C to +125C, unless otherwise specified. Typical values are at VCC = 3.3V and TA = +25C.) (Note 1)
PARAMETER CRESET AND CDLY_ CRESET Threshold CRESET Charge Current CDLY_ Threshold CDLY_ Charge Current Input Low Voltage Input High Voltage TH1, TH0 Logic-Input Floating TOL, TH1, TH0 Logic-Input Current EN_ Input Leakage Current MR Internal Pullup Current OUTPUTS (OUT_, RESET) Output Low Voltage (Open-Drain or Push-Pull) Output High Voltage (Push-Pull) Output Leakage Current (Open-Drain) Reset Timeout Period TIMING IN_ to OUT_ Propagation Delay IN_ to RESET Propagation Delay MR Minimum Input Pulse Width EN_ or MR Glitch Rejection tOFF EN_ to OUT_ Delay MR to RESET Delay tON From device enabled to device disabled From device disabled to device enabled (CDLY_ open) MR falling tDELAY+ tDELAYIN_ rising, CDLY_ open IN_ falling, CDLY_ open (Note 3) 2 280 3 30 3 s s 35 20 35 s s s ns VCC 1.2V, ISINK = 90A VOL VCC 2.25V, ISINK = 0.5mA VCC 4.5V, ISINK = 1mA VOH ILKG tRP VCC 3V, ISOURCE = 500A VCC 4.5V, ISOURCE = 800A Output not asserted low, VOUT = 28V CRESET = VCC, VCC = 3.3V CRESET open 140 190 0.030 0.8 x VCC 0.8 x VCC 1 260 0.3 0.3 0.35 V A ms V VTOL, VTH1, VTH0 = GND or VCC VEN_ = VCC or GND VCC = 3.3V -1 -100 250 535 VTH-RESET ICH-RESET VTH-CDLY ICH-CDLY VIL VIH 1.4 0.6 +1 +100 820 CRESET rising, VCC = 3.3V VCC = 3.3V CDLY_ rising, VCC = 3.3V VCC = 3.3V 0.465 380 0.95 200 0.5 500 1 250 0.535 620 1.05 300 0.4 V nA V nA V V V A nA nA SYMBOL CONDITIONS MIN TYP MAX UNITS
MAX16041/MAX16042/MAX16043
DIGITAL LOGIC INPUTS (EN_, MR, TOL, TH1, TH0)
tRST-DELAY CRESET open, IN_ falling
Note 1: Devices are production tested at TA = +25C. Limits over temperature are guaranteed by design. Note 2: Operating below the UVLO causes all outputs to go low. The outputs are guaranteed to be in the correct state for VCC down to 1.2V. Note 3: To guarantee an assertion, the minimum input pulse width must be greater than 2s.
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Dual-/Triple-/Quad-Voltage, CapacitorAdjustable, Sequencing/Supervisory Circuits MAX16041/MAX16042/MAX16043
Typical Operating Characteristics
(VCC = 3.3V, TA = +25C, unless otherwise noted.)
SUPPLY CURRENT vs. SUPPLY VOLTAGE
MAX16041 toc01
SUPPLY CURRENT vs. TEMPERATURE
VCC = 28V 55 SUPPLY CURRENT (A) 50 45 VCC = 12V 40 35 30 VCC = 3.3V MAX16041
MAX16041 toc02
NORMALIZED ADJUSTABLE THRESHOLD vs. TEMPERATURE
1.003 1.002 1.001 1.000 0.999 0.998 0.997 0.996 0.995 0.994 0.993 0.992 0.991 0.990 TOL = VCC
MAX16041 toc03
60 MAX16041 55 SUPPLY CURRENT (A) 50 45 40 35 30 2 6 10 14 18 22 26
60
NORMALIZED THRESHOLD
TOL = GND
ADJUSTABLE THRESHOLD -40 -25 -10 5 20 35 50 65 80 95 110 125 TEMPERATURE (C)
30
-40 -25 -10 5 20 35 50 65 80 95 110 125 TEMPERATURE (C)
SUPPLY VOLTAGE (V)
NORMALIZED ADJUSTABLE THRESHOLD vs. TEMPERATURE
1.003 1.002 1.001 1.000 0.999 0.998 0.997 0.996 0.995 0.994 0.993 0.992 0.991 0.990
MAX16041 toc04
OUT_ DELAY vs. CCDLY_
4500 4000 OUT_ DELAY (ms) 3500 3000 2500 2000 1500 1000
MAX16041 toc05
RESET TIMEOUT PERIOD vs. CCRESET
1200 1100 1000 900 800 700 600 500 400 300 200 100 0 0 100 200 300 400 500 600 700 800 900 1000 CCRESET (nF)
MAX16041 toc06
5000
TOL = VCC
TOL = GND
3.3V THRESHOLD -40 -25 -10 5 20 35 50 65 80 95 110 125 TEMPERATURE (C)
500 0 0 100 200 300 400 500 600 700 800 900 1000 CCDLY_ (nF)
RESET TIMEOUT PERIOD (ms)
NORMALIZED THRESHOLD
FIXED RESET TIMEOUT PERIOD vs. TEMPERATURE
189 188 187 VOUT_ (V) 186 185 184 183 182 181 180 -40 -25 -10 5 20 35 50 65 80 95 110 125 TEMPERATURE (C) 0 0 1 0.2 0.6 CRESET = VCC
MAX16041 toc07
OUT_ LOW VOLTAGE vs. SINK CURRENT
MAX16041 toc08
RESET OUTPUT LOW VOLTAGE vs. SINK CURRENT
0.9 RESET OUTPUT LOW VOLTAGE (V) 0.8 0.7 0.6 0.5 0.4 0.3 0.2 0.1 0
MAX16041 toc09
190 FIXED RESET TIMEOUT PERIOD (ms)
1.0
1.0
0.8
0.4
2
5 SINK CURRENT (mA)
3
4
6
7
0
1
2
3
4
5
6
7
SINK CURRENT (mA)
4
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Dual-/Triple-/Quad-Voltage, CapacitorAdjustable, Sequencing/Supervisory Circuits
Typical Operating Characteristics (continued)
(VCC = 3.3V, TA = +25C, unless otherwise noted.)
MAX16041/MAX16042/MAX16043
RESET OUTPUT HIGH VOLTAGE vs. SOURCE CURRENT
MAX16041 toc10
ENABLE TURN-OFF
MAX16041 toc11
ENABLE TURN-ON
MAX16041 toc12
3.5 RESET OUTPUT HIGH VOLTAGE (V) 3.0 2.5 2.0 1.5 1.0 0.5 0 0
CRESET = VCC CDLY_ = OPEN EN_ 5V/div
CRESET = VCC CDLY_ = OPEN EN_ 5V/div
OUT_ 5V/div
OUT_ 5V/div
RESET 5V/div 0.1 0.2 0.3 0.4 0.5 0.6 0.7 0.8 0.9 1.0 SOURCE CURRENT (mA) 4s/div 40ms/div
RESET 5V/div
RESET TIMEOUT DELAY
MAX16041 toc13
MR FALLING vs. RESET
MAX16041 toc14
CRESET = VCC CDLY_ = OPEN IN_ 5V/div
CRESET = VCC CDLY_ = OPEN
MR 5V/div OUT_ 5V/div RESET 5V/div RESET 5V/div 100ms/div 4s/div
MR RISING vs. RESET
MAX16041 toc15
MAXIMUM TRANSIENT DURATION vs. THRESHOLD OVERDRIVE
MAXIMUM TRANSIENT DURATION (s) 90 80 70 60 50 40 30 20 10 0 1 10 100 1000 OUTPUT ASSERTED ABOVE THIS LINE
MAX16041 toc16
100
CRESET = VCC CDLY_ = OPEN MR 5V/div
RESET 5V/div
40ms/div
THRESHOLD OVERDRIVE (mV)
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5
Dual-/Triple-/Quad-Voltage, CapacitorAdjustable, Sequencing/Supervisory Circuits MAX16041/MAX16042/MAX16043
Pin Description
PIN MAX16041 1 MAX16042 1 MAX16043 1 NAME FUNCTION Supply Voltage Input. Connect a 2.2V to 28V supply voltage to power the device. All outputs are low when VCC is below the UVLO. For noisy systems, bypass VCC to GND with a 0.1F capacitor. Monitored Input 1. When the voltage at IN1 exceeds its threshold, OUT1 goes high after the capacitor-adjustable delay period. When the voltage at IN1 falls below its threshold, OUT1 goes low after a propagation delay. Monitored Input 2. When the voltage at IN2 exceeds its threshold, OUT2 goes high after the capacitor-adjustable delay period. When the voltage at IN2 falls below its threshold, OUT2 goes low after a propagation delay. Monitored Input 3. When the voltage at IN3 exceeds its threshold, OUT3 goes high after the capacitor-adjustable delay period. When the voltage at IN3 falls below its threshold, OUT3 goes low after a propagation delay. Monitored Input 4. When the voltage at IN4 exceeds its threshold, OUT4 goes high after the capacitor-adjustable delay period. When the voltage at IN4 falls below its threshold, OUT4 goes low after a propagation delay. Threshold Tolerance Input. Connect TOL to GND to select thresholds 5% below nominal. Connect TOL to VCC to select thresholds 10% below nominal. Ground Active-High Logic-Enable Input 1. Driving EN1 low causes OUT1 to go low regardless of the input voltage. Drive EN1 high to enable the monitoring comparator. Active-High Logic-Enable Input 2. Driving EN2 low causes OUT2 to go low regardless of the input voltage. Drive EN2 high to enable the monitoring comparator. Active-High Logic-Enable Input 3. Driving EN3 low causes OUT3 to go low regardless of the input voltage. Drive EN3 high to enable the monitoring comparator. Active-High Logic-Enable Input 4. Driving EN4 low causes OUT4 to go low regardless of the input voltage. Drive EN4 high to enable the monitoring comparator. Threshold Select Input 1. Connect TH1 to VCC or GND, or leave it open to select the input-voltage threshold option in conjunction with TH0 (see Table 2). Threshold Select Input 0. Connect TH0 to VCC or GND, or leave it open to select the input-voltage threshold option in conjunction with TH1 (see Table 2). Output 4. When the voltage at IN4 is below its threshold or EN4 goes low, OUT4 goes low. Output 3. When the voltage at IN3 is below its threshold or EN3 goes low, OUT3 goes low. Output 2. When the voltage at IN2 is below its threshold or EN2 goes low, OUT2 goes low.
VCC
2
2
2
IN1
3
3
3
IN2
--
4
4
IN3
--
--
5
IN4
4 5 6
5 6 7
6 7 8
TOL GND EN1
7
8
9
EN2
--
9
10
EN3
--
--
11
EN4
8 9 -- -- 10
10 11 -- 12 13
12 13 14 15 16
TH1 TH0 OUT4 OUT3 OUT2
6
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Dual-/Triple-/Quad-Voltage, CapacitorAdjustable, Sequencing/Supervisory Circuits
Pin Description (continued)
PIN MAX16041 11 MAX16042 14 MAX16043 17 NAME OUT1 FUNCTION Output 1. When the voltage at IN1 is below its threshold or EN1 goes low, OUT1 goes low. Active-Low Reset Output. RESET asserts low when any of the monitored voltages (IN_) falls below its respective threshold, any EN_ goes low, or MR is asserted. RESET remains asserted for the reset timeout period after all of the monitored voltages exceed their respective threshold, all EN_ are high, all OUT_ are high, and MR is deasserted.
MAX16041/MAX16042/MAX16043
12
15
18
RESET
13
16
19
14
17
20
--
--
21
Active-Low Manual Reset Input. Pull MR low to assert RESET low. RESET remains low for the reset timeout period after MR is deasserted (as long as all OUT_ are high). Capacitor-Adjustable Reset Delay Input. Connect an external capacitor from CRESET to GND to set the reset timeout period or connect to VCC for the CRESET default 140ms minimum reset timeout period. Leave CRESET open for internal propagation delay. Capacitor-Adjustable Delay Input 4. Connect an external capacitor from CDLY4 CDLY4 to GND to set the IN4 to OUT4 (and EN4 to OUT4) delay period. Leave CDLY4 open for internal propagation delay. MR CDLY3 Capacitor-Adjustable Delay Input 3. Connect an external capacitor from CDLY3 to GND to set the IN3 to OUT3 (and EN3 to OUT3) delay period. Leave CDLY3 open for internal propagation delay. Capacitor-Adjustable Delay Input 2. Connect an external capacitor from CDLY2 to GND to set the IN2 to OUT2 (and EN2 to OUT2) delay period. Leave CDLY2 open for internal propagation delay. Capacitor-Adjustable Delay Input 1. Connect an external capacitor from CDLY1 to GND to set the IN1 to OUT1 (and EN1 to OUT1) delay period. Leave CDLY1 open for internal propagation delay. Exposed Pad. EP is internally connected to GND. Connect EP to the ground plane.
--
18
22
15
19
23
CDLY2
16
20
24
CDLY1
--
--
--
EP
Detailed Description
The MAX16041/MAX16042/MAX16043 are low-voltage, accurate, dual-/triple-/quad-voltage microprocessor (P) supervisors in a small TQFN package. These devices provide supervisory and sequencing functions for complex multivoltage systems. The MAX16041 monitors two voltages, the MAX16042 monitors three voltages, and the MAX16043 monitors four voltages. The MAX16041/MAX16042/MAX16043 offer independent outputs and enable functions for each monitored voltage. This configuration allows the device to operate as four separate supervisory circuits or be daisy-chained together to allow controlled sequencing of power supplies during power-up initialization. When all of the monitored
voltages exceed their respective thresholds, an independent reset output deasserts to allow the system processor to operate. These devices offer enormous flexibility as there are nine threshold options that are selected through two threshold-select logic inputs. Each monitor circuit also offers an independent enable input to allow both digital and analog control of each monitor output. A tolerance select input allows these devices to be used in systems requiring 5% or 10% power-supply tolerances. In addition, the time delays and reset timeout can be adjusted using small capacitors. There is also a fixed 140ms minimum reset timeout feature.
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7
Dual-/Triple-/Quad-Voltage, CapacitorAdjustable, Sequencing/Supervisory Circuits MAX16041/MAX16042/MAX16043
TH0 TH1 EN4 EN3 EN2 EN1 DELAY
IN1
THRESHOLD SELECT LOGIC
250nA
LOGIC
DRIVER
OUT1
1V
IN2
MAX16043
DELAY
DRIVER
OUT2
IN3
DELAY
DRIVER
OUT3
IN4
DELAY
DRIVER
OUT4
GND RESET DELAY LOGIC TOL REFERENCE DRIVER RESET
VCC
CDLY1
CDLY2
CDLY3
CDLY4
CRESET
MR
Figure 1. MAX16043 Simplified Functional Diagram
8
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Dual-/Triple-/Quad-Voltage, CapacitorAdjustable, Sequencing/Supervisory Circuits MAX16041/MAX16042/MAX16043
VCC VUVLO
IN_
VTH
VTH t < tON
EN_
OUT_
tDELAYtON tDELAY+ tRST_DELAY tRP RESET tRP tOFF
tON
tRP
Figure 2. Timing Diagram (CDLY_ Open)
Applications Information
Tolerance
The MAX16041/MAX16042/MAX16043 feature a pinselectable threshold tolerance. Connect TOL to GND to select the thresholds 5% below the nominal value. Connect TOL to VCC to select the threshold tolerance 10% below the nominal voltage. Do not leave TOL unconnected.
shown in Figure 3 and use the following equation to calculate the threshold voltage: R1 VINTH = VTH x 1 + R2 Choosing the proper external resistors is a balance between accuracy and power use. The input to the voltage monitor is a high-impedance input with a small 100nA leakage current. This leakage current contributes to the overall error of the threshold voltage where the output is asserted. This induced error is proportional to the value of the resistors used to set the threshold. With lower value resistors, this error is reduced, but the amount of power consumed in the resistors increases.
Adjustable Input
These devices offer several monitoring options with both fixed and/or adjustable reset thresholds (see Table 2). For the adjustable threshold inputs, the threshold voltage (VTH) at each adjustable IN_ input is typically 0.5V (TOL = GND) or 0.472V (TOL = VCC). To monitor a voltage VINTH, connect a resistive divider network to the circuit as
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9
Dual-/Triple-/Quad-Voltage, CapacitorAdjustable, Sequencing/Supervisory Circuits MAX16041/MAX16042/MAX16043
VINTH R1 IN_
OUT_ Output
The MAX16041/MAX16042/MAX16043 feature open-drain outputs. An OUT_ goes low when its respective IN_ input voltage drops below its specified threshold or when its EN_ goes low (see Table 1). OUT_ goes high when EN_ is high and VIN_ is above its threshold after a time delay. Open-drain outputs require an external pullup resistor to any voltage from 0 to 28V.
MAX16041 MAX16042 MAX16043
R2
Table 1. Output State*
VTH VINTH -1 R1 = R2 x VTH
EN_ Low
IN_ VIN_ < VTH VIN_ < VTH VIN_ > VTH VIN_ > VTH Low Low Low
OUT_
(
)
High Low High
OUT_ = high impedance
Figure 3. Setting the Adjustable Input
The following equation is provided to help estimate the value of the resistors based on the amount of acceptable error: e x VINTH R1 = A IL where eA is the fraction of the maximum acceptable absolute resistive divider error attributable to the input leakage current (use 0.01 for 1%), VINTH is the voltage at which the output (OUT_) should assert, and IL is the worst-case IN_ leakage current (see the Electrical Characteristics). Calculate R2 as follows: VTH x R1 R2 = VINTH - VTH
*When VCC falls below the UVLO, all outputs go low regardless of the state of EN_ and VIN_. The outputs are guaranteed to be in the correct state for VCC down to 1.2V.
Table 2. Input-Voltage Threshold Selector
TH1/TH0 LOGIC Low/Low Low/High Low/Open High/Low High/High High/Open Open/Low Open/High Open/Open IN1 (ALL IN2 (ALL IN3 IN4 VERSIONS) VERSIONS) (MAX16042) (MAX16043) (V) (V) (V) (V) 3.3 3.3 3.3 3.3 2.5 3.3 3.3 2.5 Adj 2.5 1.8 1.5 1.2 1.8 Adj Adj Adj Adj 1.8 Adj Adj 1.8 Adj 2.5 Adj Adj Adj 1.5 Adj Adj 2.5 Adj Adj Adj Adj Adj
Unused Inputs
Connect any unused IN_ and EN_ inputs to VCC.
RESET Output
RESET asserts low when any of the monitored voltages (IN_) falls below its respective threshold, any EN_ goes low, or MR is asserted. RESET remains asserted for the reset timeout period after all of the monitored voltages exceed their respective thresholds, all EN_ are high, all OUT_ are high, and MR is deasserted. All devices have a push-pull, active-low reset output.
10
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Dual-/Triple-/Quad-Voltage, CapacitorAdjustable, Sequencing/Supervisory Circuits
Adjustable Reset Timeout Period (CRESET)
All of these parts offer an internally fixed reset timeout (140ms min) by connecting CRESET to VCC. The reset timeout can also be adjusted by connecting a capacitor from CRESET to GND. When the voltage at CRESET reaches 0.5V, RESET goes high. When RESET goes high, CRESET is immediately held low. Calculate the reset timeout period as follows: Connect a normally open momentary switch from MR to GND to create a manual-reset function. External debounce circuitry is not required. If MR is driven from long cables or if the device is used in a noisy environment, connect a 0.1F capacitor from MR to GND to provide additional noise immunity.
MAX16041/MAX16042/MAX16043
Pullup Resistor Values
The exact value of the pullup resistors for the opendrain outputs is not critical, but some consideration should be made to ensure the proper logic levels when the device is sinking current. For example, if VCC = 2.25V and the pullup voltage is 28V, keep the sink current less than 0.5mA as shown in the Electrical Characteristics. As a result, the pullup resistor should be greater than 56k. For a 12V pullup, the resistor should be larger than 24k. Note that the ability to sink current is dependent on the VCC supply voltage.
V tRP = TH-RESET x CCRESET + 30 x 10 -6 ICH-RESET where VTH-RESET is 0.5V, ICH-RESET is 0.5A, tRP is in seconds, and CCRESET is in Farads. To ensure timing accuracy and proper operation, minimize leakage at CCRESET.
Power-Supply Bypassing
The device operates with a VCC supply voltage from 2.2V to 28V. When VCC falls below the UVLO threshold, all the outputs go low and stay low until VCC falls below 1.2V. For noisy systems or fast rising transients on VCC, connect a 0.1F ceramic capacitor from VCC to GND as close to the device as possible to provide better noise and transient immunity.
Adjustable Delay (CDLY_)
When VIN rises above VTH with EN_ high, the internal 250nA current source begins charging an external capacitor connected from CDLY_ to GND. When the voltage at CDLY_ reaches 1V, OUT_ goes high. When OUT_ goes high, CDLY_ is immediately held low. Adjust the delay (tDELAY) from when VIN rises above VTH (with EN_ high) to OUT_ going high according to the equation: V tDELAY = TH- CDLY x CCDLY + 35 x 10 -6 ICH- CDLY where VTH-CDLY is 1V, ICH-CDLY is 0.25A, CCDLY is in Farads, and tDELAY is in seconds. To ensure timing accuracy and proper operation, minimize leakage at CDLY.
Ensuring Valid Reset Output with VCC Down to 0V
When VCC falls below 1.2V, the ability for the output to sink current decreases. To ensure a valid output as VCC falls to 0V, connect a 100k resistor from RESET to GND.
Typical Application Circuits
Figures 4 and 5 show typical applications for the MAX16041/MAX16042/MAX16043. In high-power applications, using an n-channel device reduces the loss across the MOSFETs as it offers a lower drain-to-source on-resistance. However, an n-channel MOSFET requires a sufficient VGS voltage to fully enhance it for a low R DS_ON. The application in Figure 4 shows the MAX16042 configured in a multiple-output sequencing application. Figure 5 shows the MAX16043 in a powersupply sequencing application using n-channel MOSFETs.
Manual-Reset Input (MR)
Many P-based products require manual-reset capability, allowing the operator, a test technician, or external logic circuitry to initiate a reset. A logic-low on MR asserts RESET low. RESET remains asserted while MR is low and during the reset timeout period (140ms fixed or capacitor adjustable) after MR returns high. The MR input has a 500nA internal pullup, so it can be left unconnected, if not used. MR can be driven with TTL or CMOS logic levels, or with open-drain/collector outputs.
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11
Dual-/Triple-/Quad-Voltage, CapacitorAdjustable, Sequencing/Supervisory Circuits MAX16041/MAX16042/MAX16043
3.3V
+2.5V IN DC-DC EN OUT IN DC-DC EN OUT
+1.8V IN DC-DC EN OUT
+1.5V
EN1 VCC TH0 TH1 MR CDLY1
IN1
OUT1
EN2
IN2
OUT2
EN3
IN3 OUT3
MAX16042
RESET CDLY2 CDLY3 CRESET GND TOL SYSTEM RESET
Figure 4. Sequencing Multiple-Voltage System
12V BUS 1.5V
1.8V TO LOADS 2.5V
3.3V IN1 OUT1 IN2 OUT2 IN3 OUT3 IN4 OUT4
VCC EN1 EN2 EN3 EN4
MAX16043
RESET CDLY1 CDLY2 CDLY3 CDLY4 CRESET GND TOL TH0 TH1 MR
SYSTEM RESET
Figure 5. Multiple-Voltage Sequencing Using n-Channel FETs
12 ______________________________________________________________________________________
Dual-/Triple-/Quad-Voltage, CapacitorAdjustable, Sequencing/Supervisory Circuits
Pin Configurations (continued)
TOP VIEW
RESET RESET OUT1 OUT2 OUT1 OUT2 OUT3 TH0 TH0
MAX16041/MAX16042/MAX16043
12
11
10
9
15 MR 16 CRESET 17 CDLY3 18 6 5 EN1 CDLY2 19 GND
14
13
12
11 10 9 TH1 EN3 EN2 EN1 GND
MR 13 CRESET 14 CDLY2 15 CDLY1 16
8 7
TH1 EN2
MAX16041
MAX16042
8 7 6
CDLY1 20
+
1 VCC
2 IN1
3 IN2
4 TOL
+
1 VCC
2 IN1
3 IN2
4 IN3
5 TOL
TQFN (4mm x 4mm)
TQFN (4mm x 4mm)
Chip Information
PROCESS: BICMOS
______________________________________________________________________________________
13
Dual-/Triple-/Quad-Voltage, CapacitorAdjustable, Sequencing/Supervisory Circuits MAX16041/MAX16042/MAX16043
Package Information
(The package drawing(s) in this data sheet may not reflect the most current specifications. For the latest package outline information go to www.maxim-ic.com/packages.) 24L QFN THIN.EPS
PACKAGE OUTLINE, 12, 16, 20, 24, 28L THIN QFN, 4x4x0.8mm
21-0139
E
1 2
14
______________________________________________________________________________________
Dual-/Triple-/Quad-Voltage, CapacitorAdjustable, Sequencing/Supervisory Circuits
Package Information (continued)
(The package drawing(s) in this data sheet may not reflect the most current specifications. For the latest package outline information go to www.maxim-ic.com/packages.)
MAX16041/MAX16042/MAX16043
PACKAGE OUTLINE, 12, 16, 20, 24, 28L THIN QFN, 4x4x0.8mm
21-0139
E
2 2
Maxim cannot assume responsibility for use of any circuitry other than circuitry entirely embodied in a Maxim product. No circuit patent licenses are implied. Maxim reserves the right to change the circuitry and specifications without notice at any time.
Maxim Integrated Products, 120 San Gabriel Drive, Sunnyvale, CA 94086 408-737-7600 ____________________ 15
(c) 2006 Maxim Integrated Products is a registered trademark of Maxim Integrated Products, Inc.

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