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19-3964; Rev 3; 2/08
45V, 400mA, Low-Quiescent-Current Linear Regulator with Adjustable Reset Delay
General Description
The MAX5087 high-voltage linear regulator operates from an input voltage of 6.5V to 45V and delivers up to 400mA of output current. The device consumes only 70A of quiescent current with no load and 11A in shutdown. The device includes a SET input, that when connected to ground, selects a preset output voltage of 3.3V (MAX5087A) or 5.0V (MAX5087B). Alternatively, the output voltage can be adjusted from 2.5V to 11V by simply connecting SET to the regulator's output through a resistive divider network. The MAX5087 also provides an open-drain, active-low microprocessor (P) reset output that asserts when the regulator output drops below the preset output voltage threshold. An external capacitor programs the reset timeout period. Other features include an enable input, thermal shutdown, and short-circuit protection. The MAX5087 operates over the automotive temperature range of -40C to +125C and is available in a 16pin TQFN thermally enhanced package.
Features
Wide Operating Input Voltage Range (6.5V to 45V) Thermally Enhanced Package Dissipates 2.6W at TA = +70C (16-Pin TQFN) Guaranteed 400mA Output Current 70A Quiescent Supply Current Preset 3.3V, 5.0V, or Adjustable 2.5V to 11V Output Voltage Remote Load Sense Capability Enable Input Integrated P Reset Circuit with Programmable Timeout Period Thermal and Short-Circuit Protection -40C to +125C Operating Temperature Range
MAX5087
Ordering Information
PART MAX5087AATE+ MAX5087BATE+ PINPACKAGE 16 TQFN-EP* 16 TQFN-EP* PKG CODE T1655-2 T1655-2 OUTPUT VOLTAGE (V) 3.3 5.0
Applications
Automotive Industrial Home Security/Safety Networking
Note: All devices are specified over the -40C to +125C operating temperature range. *EP = Exposed paddle. +Denotes lead-free package.
Pin Configuration
TOP VIEW
RESET 10
N.C.
12 N.C. N.C. N.C. N.C. 13 14 15 16
11
SET 9 8 7 GND OUTSENSE
OUT OUT
MAX5087
CT
6 5
+
1 N.C. 2 EN 3 IN 4 IN
TQFN
________________________________________________________________ Maxim Integrated Products
1
For pricing, delivery, and ordering information, please contact Maxim Direct at 1-888-629-4642, or visit Maxim's website at www.maxim-ic.com.
45V, 400mA, Low-Quiescent-Current Linear Regulator with Adjustable Reset Delay MAX5087
ABSOLUTE MAXIMUM RATINGS
IN to GND (do not exceed package power dissipation) .........................................................-0.3V to +50V IN to GND (T 300ms, IOUT 250mA) ..................-0.3V to +42V EN to GND..............................................................-0.3V to +50V RESET, OUT, OUTSENSE to GND .........................-0.3V to +12V IN to OUT................................................................-0.3V to +50V CT, SET TO GND....................................................-0.3V to +35V Short-Circuit Duration (VIN 14V) ..............................Continuous Maximum Current into Any Pin (Except IN, OUT).............20mA Continuous Power Dissipation (TA = +70C) 16-Pin TQFN (derate 33.3mW/C above +70C) ......2666mW* Thermal Resistance (Note 1) JA, 16-Pin TQFN ......................................................30.0C/W JC, 16-Pin TQFN ...........................................................2C/W Operating Temperature Range .........................-40C to +125C Junction Temperature ......................................................+150C Storage Temperature Range .............................-60C to +150C Lead Temperature (soldering, 10s) .................................+300C
Note 1: Package thermal resistances were obtained using the method described in JEDEC specification JESD51-7 using a fourlayer board. For detailed information on thermal considerations, refer to www.maxim-ic.com/thermal-tutorial.
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
(VIN = 14V, IOUT = 1mA, CIN = 47F (low ESR), COUT = 15F, VEN = 2.4V, 10k from RESET to OUT, TA = TJ = -40C to +125C, unless otherwise noted. Typical specifications are at TA = +25C.) (Note 2)
PARAMETER Input Voltage Range Supply Current Shutdown Supply Current REGULATOR Guaranteed Output Current IOUT VIN = 6.5V, VOUT = 5.0V SET = GND, 5V version Output Voltage (Note 3) VOUT SET = GND, 3.3V version 6.5V VIN 25V, 5mA IOUT 400mA 6.5V VIN 45V, 5mA IOUT 100mA 6.5V VIN 25V, 5mA IOUT 400mA 6.5V VIN 45V, 5mA IOUT 100mA 400 4.87 4.850 3.208 3.208 2.5 0.9 400 -1 -0.5 2.4 0.4 +1 +0.5 5 5 3.3 3.3 5.13 5.150 3.392 3.392 11.0 2.2 V s mV/V V V mA SYMBOL VIN IQ ISHDN CONDITIONS VIN VOUT + 1.5V Measured at GND, SET = GND VEN 0.4V IOUT = 0 IOUT = 400mA MIN 6.5 70 5300 11 21 TYP MAX 45.0 150 UNITS V A A
IOUT = 5mA, adjustable range Dropout Voltage Startup Response Time Line Regulation Enable Voltage VOUT / VIN VEN VDO IOUT = 400mA, VOUT = 5V (Note 4) Rising edge of VIN to VOUT, RL = 500, SET = GND (Note 5) 8V VIN 45V 5V version 3.3V version
VEN = high, regulator on VEN = low, regulator off
2
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45V, 400mA, Low-Quiescent-Current Linear Regulator with Adjustable Reset Delay
ELECTRICAL CHARACTERISTICS (continued)
(VIN = 14V, IOUT = 1mA, CIN = 47F (low ESR), COUT = 15F, VEN = 2.4V, 10k from RESET to OUT, TA = TJ = -40C to +125C, unless otherwise noted. Typical specifications are at TA = +25C.) (Note 2)
PARAMETER Enable Input Current SET Reference Voltage SET Input Leakage Current Load Regulation Power-Supply Rejection Ratio Short-Circuit Current Thermal Shutdown Temperature Thermal Shutdown Hysteresis RESET Voltage Threshold RESET Threshold Hysteresis RESET Output Low Voltage RESET Output Leakage Current RESET Output Minimum Timeout Period ENABLE to RESET Minimum Timeout Period Delay Comparator Threshold (Rising) Delay Comparator Threshold Hysteresis CT Charge Current CT Discharge Current 1 SYMBOL IEN VSET ISET VOUT / IOUT PSRR ISC TJ(SHDN) TJ(SHDN) VRESET VRHYST VRL IRH ISINK = 1mA VRESET = 5V When VOUT reaches RESET threshold, CCT = Open When EN goes high, CCT = open 1.196 15 170 1.230 100 2 5 4 1.264 89 IOUT = 1mA to 400mA (Note 3) IOUT = 10mA, f = 100Hz, 500mVP-P, VOUT = 5V VIN < 14V (Note 6) VEN = 2.4V VEN = 14V 1.200 -100 CONDITIONS MIN TYP 0.35 3.4 1.235 +0.5 0.1 70 640 175 25 92 2 0.4 1 94 1.260 +100 0.35 MAX UNITS A V nA dB mA C C % VOUT % VOUT V A s s V mV A mA
MAX5087
Note 2: Note 3: Note 4: Note 5: Note 6:
Limits at TA = -40C are guaranteed by design. Output voltage is tested using a pulsed load current of less than 50ms duration. Dropout voltage is defined as (VIN - VOUT) when VOUT is 100mV below the value of VOUT for VIN = VOUT + 3V. Startup time measured from 50% of VIN to 90% of VOUT. Continuous short-circuit protection for VIN > 14V not guaranteed.
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45V, 400mA, Low-Quiescent-Current Linear Regulator with Adjustable Reset Delay MAX5087
Typical Operating Characteristics
(VIN = VEN = 14V, CIN = 47F (low ESR), COUT = 15F, VOUT = 5V, SET = GND, TA = +25C, unless otherwise specified.)
OUTPUT VOLTAGE vs. INPUT VOLTAGE
MAX5087 toc01
NO-LOAD SUPPLY CURRENT vs. TEMPERATURE
MAX5087 toc02
SHUTDOWN SUPPLY CURRENT vs. TEMPERATURE
18 16 14 ISHDN (A) 12 10 8 6 4 2 0
MAX5087 toc03
5.5 5.0 4.5 4.0 3.0 2.5 2.0 1.5 1.0 0.5 0 0 5 10 15 20 25 30 35 40 IOUT = 0 3.5 VOUT (V)
120 110 100 90 IGND (A) 80 70 60 50 40 30 20 10 0
20
VIN = +45V
VIN = +14V VIN = +6.5V
45
-40 -25 -10 5 20 35 50 65 80 95 110 125 TEMPERATURE (C)
-40 -25 -10 5 20 35 50 65 80 95 110 125 140 TEMPERATURE (C)
VIN (V)
OUTPUT VOLTAGE vs. TEMPERATURE
MAX5087 toc04
GROUND CURRENT vs. TEMPERATURE (PULSED LOAD)
MAX5087 toc05
OUTPUT VOLTAGE vs. LOAD CURRENT AND TEMPERATURE
5.20 5.15 5.10 VOUT (V) IOUT = 50mA IOUT = 100mA VIN = +6.5V
MAX5087 toc06
5.25 5.20 5.15 5.10
6 VIN = +6.5V 5 4 IGND (mA) IOUT = 400mA 3 2 1
5.25
VOUT (V)
5.05 5.00 4.95 4.90 4.85 4.80 4.75 TEMPERATURE (C) IOUT = 5mA
5.05 5.00 4.95
IOUT = 50mA
IOUT = 100mA
4.90 4.85 4.80
IOUT = 400mA
0 -40 -25 -10 5 20 35 50 65 80 95 110 125 140 -40 -25 -10 5 20 35 50 65 80 95 110 125 140 TEMPERATURE (C)
4.75 -40 -25 -10 5 20 35 50 65 80 95 110 125 140 TEMPERATURE (C)
DROPOUT VOLTAGE vs. LOAD CURRENT
MAX5087 toc07
POWER-SUPPLY REJECTION RATIO vs. FREQUENCY
-10 -20 PSRR (dB) -30 -40 -50 -60 -70 COUT = 15F IOUT = 10mA
MAX5087 toc08
LOAD-TRANSIENT RESPONSE
MAX5087 toc09
1.50 1.35 1.20 1.05 VDROPOUT (V) 0.90 0.75 0.60 0.45 0.30 0.15 0 0 50 VOUT = +5V
0
IOUT = 5mA VOUT 200mV/div AC-COUPLED
400mA IOUT 200mA/div 5mA 0.1 1 10 FREQUENCY (kHz) 100 1000
-80 100 150 200 250 300 350 400 IOUT (mA) 400s/div
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45V, 400mA, Low-Quiescent-Current Linear Regulator with Adjustable Reset Delay
Typical Operating Characteristics (continued)
(VIN = VEN = 14V, CIN = 47F (low ESR) COUT = 15F, VOUT = 5V, SET = GND, TA = +25C, unless otherwise specified.)
MAX5087
INPUT VOLTAGE STEP RESPONSE
MAX5087 toc10
STARTUP RESPONSE
MAX5087 toc11
ENABLE STARTUP RESPONSE
MAX5087 toc12
IOUT = 50mA VOUT AC-COUPLED 500mV/div 0V
IOUT = 5mA EN 1V/div 0V
VOUT 2V/div
26V VIN 10V/div 6.5V
VIN 10V/div 0V 0V 400s/div 100s/div VIN = 14V IOUT = 0
VOUT 2V/div
400s/div
ENABLE STARTUP RESPONSE
MAX5087 toc13
ENABLE STARTUP RESPONSE
MAX5087 toc14
ENABLE STARTUP RESPONSE
MAX5087 toc15
EN 1V/div 0V 0V
EN 1V/div 0V
EN 1V/div
VOUT 2V/div 0V VIN = 14V IOUT = 400mA 100s/div 0V 100s/div VIN = 45V IOUT = 0
VOUT 2V/div 0V VIN = 45V IOUT = 400mA 100s/div
VOUT 2V/div
SHUTDOWN RESPONSE
MAX5087 toc16
GROUND CURRENT DISTRIBUTION (TA = -40C)
MAX5087 toc17
GROUND CURRENT DISTRIBUTION (TA = +125C)
35 30 NUMBER OF UNITS 25 20 15 10 5 0 150 UNITS TESTED
MAX5087 toc18
40 35 EN 1V/div NUMBER OF UNITS 30 25 20 15 10 5 0 51 52 53 54 55 56 57 58 59 60 61 62 63 64 65 IGND (A) 150 UNITS TESTED
40
0V
IOUT = 5mA
0V VOUT 2V/div
20ms/div
63 65 66 67 68 69 70 71 72 73 74 75 76 IGND (A)
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5
45V, 400mA, Low-Quiescent-Current Linear Regulator with Adjustable Reset Delay MAX5087
Pin Description
PIN 1, 12-16 2 3, 4 5, 6 7 8 9 NAME N.C. EN IN OUT OUTSENSE GND SET No Connection. Not internally connected. Enable Input. Drive EN high to turn on the regulator. Force EN low to place the device in shutdown mode. Regulator Input. Supply voltage ranges from 6.5V to 45V. Bypass IN to GND with a low-ESR 47F electrolytic capacitor. Regulator Output. Connect at least a 15F low-ESR capacitor from OUT to GND. Regulator Output Feedback Point. OUTSENSE must be connected to OUT for fixed output voltage versions. Leave OUTSENSE open for adjustable output voltage version. Ground Feedback Regulation Set Point. Connect SET to GND for a fixed 3.3V output (MAX5087A) or 5.0V output (MAX5087B). Connect an external resistive divider network from OUTSENSE to SET to GND to adjust the output voltage from 2.5V to 11V. Open-Drain Active-Low Reset Output. Connect a 10k pullup resistor from RESET to any supply voltage up to 11V to create a logic output. Reset Timeout Setting Connection. A 2A charging current is available at CT. Connect a capacitor from CT to GND to set the reset timeout period (see the Adjustable Reset Timeout Period (CT) section). Exposed Paddle. Connect externally to a large ground plane to aid heat dissipation. Do not use EP as a ground connection. FUNCTION
10 11 --
RESET CT EP
6
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45V, 400mA, Low-Quiescent-Current Linear Regulator with Adjustable Reset Delay MAX5087
IN
MAX5087
VREF 1.235V CONTROL LOGIC, THERMAL SHUTDOWN, AND OVERCURRENT PROTECTION INTERNAL SUPPLY VOLTAGE
ERROR AMPLIFIER
OUT OUTSENSE
EN
MUX
SET 2A CT CT COMPARATOR DELAY COMPARATOR
RESET
0.92 x VREF
GND
Figure 1. Functional Diagram
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45V, 400mA, Low-Quiescent-Current Linear Regulator with Adjustable Reset Delay MAX5087
Detailed Description
The MAX5087 high-voltage linear regulator includes an integrated P reset circuit with an adjustable reset timeout period (see the Adjustable Reset Timeout Period (CT) section). The device guarantees a 400mA load current and is available with a preset output voltage of 3.3V (MAX5087A) or 5V (MAX5087B). Both devices can be configured to provide an adjustable output voltage from 2.5V to 11V. The internal reset circuit monitors the regulator output voltage and asserts RESET low when the regulator output falls below the reset threshold voltage. Other features include an enable (regulator control input), 21A (max) shutdown current, short-circuit protection (see the Output Short-Circuit Current Limit section), and thermal shutdown (see the Thermal Protection section).
6.5V TO 45V IN 47F R1 ON OFF TO P EN RESET CT CCT GND R2 SET OUT 15F 2.5V TO 11V
MAX5087
OUTSENSE
Regulator
The MAX5087 accepts an input voltage range from 6.5V to 45V and offers a fixed output voltage of 3.3V or 5V. For an adjustable output voltage operation, use an external resistive divider network connected between OUT, SET, and GND (see Figure 2).
VOUT = VSET (1 + R1 / R2) VSET = 1.235V
Figure 2. Setting the Adjustable Output Voltage
Enable Input (EN)
EN is a logic-level enable input that turns the device on/off. Drive EN high to turn on the device and drive EN low to place the device in shutdown. The MAX5087 draws 11A (typ) of supply current when in shutdown. EN withstands voltages up to +45V, allowing EN to be connected to IN for an always-on operation.
timeout period (see Figure 2) and use the following equation to calculate the timeout period: tRP = CCT x 0.6175 x 106 (s) where CCT is the value of the external capacitor connected from CT to GND.
Thermal Protection
When the junction temperature exceeds TJ = +175C, an internal thermal sensor signals the shutdown logic, which turns off the pass transistor, allowing the IC to cool. The thermal sensor turns the pass transistor on again after the IC's junction temperature cools by 25C, resulting in a cycled output during continuous thermaloverload conditions. Thermal protection protects the MAX5087 in the event of fault conditions. During continuous operation, do not exceed the absolute maximum junction temperature rating of TJ = +150C.
Remote Sensing (OUTSENSE)
The 3.3V (MAX5087A) and 5V (MAX5087B) output voltage versions connect OUTSENSE for load voltage sensing. Leave OUTSENSE open when using adjustable output voltage version.
Reset Output (RESET)
A supervisor circuit is fully integrated in the MAX5087 and uses the same reference voltage as the regulator. RESET goes low if VOUT drops below the preset output voltage threshold, and remains low at least for the timeout period after VOUT rises above the reset voltage threshold.
Output Short-Circuit Current Limit
The MAX5087 features a current limit. The output can be shorted to GND for an indefinite period of time (for VIN < 14V) without damage to the device. Continuous output short-circuit protection is only guaranteed for VIN < 14V.
Adjustable Reset Timeout Period (CT)
The MAX5087 features a user-adjustable reset timeout. Connect a capacitor from CT to GND to set the reset
8
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45V, 400mA, Low-Quiescent-Current Linear Regulator with Adjustable Reset Delay
Applications Information
The MAX5087 features a Dual ModeTM operation, in either a preset-voltage mode or an adjustable mode. In preset-voltage mode, internal feedback resistors set the MAX5087's output voltage to +3.3V or +5V. Select preset-voltage mode by connecting SET to ground. In adjustable mode, select an output between +2.5V and +11V using two external resistors connected as a voltage-divider to SET (Figure 2). Set the output voltage using the following equation: R1 VOUT = VSET x 1 + R2 where VSET = 1.235V and R2 is chosen to be < 100k.
3.5 3.0 2.5 PD (W) 2.0 1.5 1.0 0.5 0 0 20 40 60 80 100 120 140 TEMPERATURE (C) 2.666W (16-PIN TQFN) DERATE 33.3mW/C
MAX5087 fig03
MAX5087
Output-Voltage Selection
4.0
Available Output-Current Calculation
The MAX5087 high-voltage regulator provides up to 400mA of output current. The input voltage extends to +45V. Package power dissipation limits the amount of output current available for a given input/output voltage and ambient temperature. Figure 3 shows the maximum power dissipation curve for these devices. The graph assumes that the exposed paddle of the MAX5087 package is set up per JEDEC 51 (multilayer board) specifications. Use Figure 3 to determine the allowable package dissipation (P D ) for a given ambient temperature. Alternately, use the following formulas to calculate the allowable package dissipation. Note that for the examples shown below, the electrical characteristic limits are guaranteed up to TJ = +125C (max).
2.666W for TA + 70C PD = W 2.666W - 0.0333 C x (TA - 70C) for + 70C < TA + 125C
Figure 3. Calculated Maximum Power Dissipation vs. Temperature
The above equations do not include the negligible power dissipation from self-heating due to the IC ground current. Example 1: TA = +95C VIN = +14V VOUT = +5V Find the maximum allowable output current. First calculate package dissipation at the given temperature as follows:
PD = 2.666W - 0.0333 W (95C - 70C) = 1.8335W C
Then determine the maximum output current: IOUT(MAX) = (1.8335W) = 203mA (14V) - (5V)
After determining the allowable package dissipation calculate the maximum output current using the following formula: IOUT(MAX) PD 400mA VIN - VOUT
Example 2: TA = +125C VIN = +14V VOUT = +5V
Dual Mode is a trademark of Maxim Integrated Products, Inc. _______________________________________________________________________________________ 9
45V, 400mA, Low-Quiescent-Current Linear Regulator with Adjustable Reset Delay MAX5087
Calculate package dissipation at the given temperature as follows:
PD = 2.666W - 0.0333 W (125C - 70C) = 0.8345W C
IOUT(MAX) (A) 0.45 0.40 0.35 0.30 0.25 0.20 0.15 0.10 0.05 0 0 5 10 15 20 25 30 35 40 45 VIN (V) VOUT = +5V
MAX5087 fig04
0.50
And establish the maximum current: IOUT(MAX) = Example 3: TA = +50C VIN = +14V VOUT = +10V Calculate package dissipation at the given temperature as follows: PD = 2.666W And find the maximum output current:
(2.666W) IOUT(MAX) = = 666mA IOUT(MAX) = 400mA (14V) - (10V)
TA = +70C TA = +85C TA = +125C
(1.191W) = 92.7mA (14V) - (5V)
Figure 4. Maximum Output Current vs. Input Voltage (16-Pin TQFN)
In example 3 the maximum output current is calculated as 666mA, however, the maximum output current cannot exceed 400mA. Use Figure 4 to quickly determine maximum allowable output current for selected ambient temperatures.
Some ceramic capacitor dielectrics exhibit large capacitance and ESR variation with temperature. For capacitor dielectrics such as Y5V, use 22F or more to ensure stability at temperatures below -10C. With X7R or X5R dielectrics, 15F should be sufficient at all operating temperatures. To improve power supply rejection and transient response, use a minimum 47F low-ESR capacitor from IN to GND.
Output-Capacitor Selection and Regulator Stability
For stable operation over the full temperature range and with load currents up to 400mA, use a 15F (min) output capacitor with an ESR < 0.25. To reduce noise and improve load-transient response, stability, and power-supply rejection use larger output capacitor values such as 22F.
Chip Information
PROCESS: BiCMOS
10
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45V, 400mA, Low-Quiescent-Current Linear Regulator with Adjustable Reset Delay
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.)
MAX5087
______________________________________________________________________________________
QFN THIN.EPS
11
45V, 400mA, Low-Quiescent-Current Linear Regulator with Adjustable Reset Delay MAX5087
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.)
12
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45V, 400mA, Low-Quiescent-Current Linear Regulator with Adjustable Reset Delay
Revision History
REVISION NUMBER 0 1 2 3 REVISION DATE 2/06 4/06 7/06 2/08 Initial release Updated Ordering Information and Electrical Characteristics tables. Updated Electrical Characteristics table. Corrected errors in data sheet, reduced operating range, and removed products from Ordering Information table. DESCRIPTION PAGES CHANGED -- 1-3 2 1-13
MAX5087
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 ____________________ 13 (c) 2008 Maxim Integrated Products is a registered trademark of Maxim Integrated Products, Inc.

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