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FAN5035
High Performance Programmable DC-DC Controller
Features
* Programmable output from 1.3V to 3.5V using an integrated 5-bit DAC * Remote sense * 1MHz operation * 85% efficiency typical at full load * Integrated Power Good and Enable/Soft Start functions * Uncommitted Op-amp * Drives N-channel MOSFETs * Over-current and over-voltage protection * 24 pin TSSOP package
Description
The FAN5035 is a voltage-mode DC-DC controller IC which provides a highly accurate, programmable output voltage for high-performance processors. The FAN5035 features remote voltage sensing, adjustable current limit and 1MHz operation. The FAN5035 uses a 5-bit D/A converter to program the output voltage from 1.3V to 3.5V. An on-board precision low TC reference achieves tight tolerance voltage regulation without expensive external components. The FAN5035 also offers integrated functions including Power Good, Output Enable/Soft Start, current limiting, over-voltage protection, and an uncommitted op-amp, and is available in a 24 pin TSSOP package.
Applications
* Power supply for Pentium(R) III * VRM for Pentium III processor * Programmable step-down power supply
Block Diagram
+5V VIN 14 OVP OSC 9 VCC
24
17 16 15 19 A3 20 18 + + + A1 Digital Control ISC +
12 OUTA 13 GNDD
7 IFB 6 11
21
5-Bit DAC 12345 VID0 VID2 VID4 VID1 VID3 22
OVP 10 OVP 8 VSENSE 23 ENABLE/SS
Power Good
PWRGD
GNDA
Pentium is a registered trademark of Intel Corporation.
REV. 1.0.0 10/31/01
PRODUCT SPECIFICATION
FAN5035
Pin Assignments
D0 D1 D2 D3 D4 IFB_HI IFB_LO VSENSE VCC OVP PWRGOOD OUTA 1 2 3 4 5 6 7 8 9 10 11 12 FAN5035 24 23 22 21 20 19 18 17 16 15 14 13 COSC EN_SS GNDA VREF A3_INN A3_OUT A3_INP A1_OUT A1_INN A1_INP VIN GNDD
Pin Definitions
Pin Number 1-5 Pin Name D0-4 Pin Function Description Voltage Identification Code Inputs. These open collector/TTL compatible inputs will program the output voltage over the ranges specified in Table 1. Pull-up resistors are internal to the controller. Current Feedback. These pins are the input for the current feedback control loop. Layout of these traces is critical to system performance. Voltage Sense. Pin 8 is used as the input for Power Good and over-voltage protection. Analog VCC. Connect to system 5V supply and decouple with a 0.1F ceramic capacitor. Over-Voltage Protection. This pin drives an SCR when the output voltage is too high. Power Good Flag. An open collector output that will be logic LOW if the output voltage is not within 10% of the nominal output voltage setpoint. Output. Connect this pin to a driver for an N-channel MOSFET. The trace from this pin to the driver should be <0.5". Power Ground. Return pin for high currents flowing in pin 12 (OUTA). Connect to a low impedance ground. Input Voltage. Under-voltage detector input. Uncommitted Op Amp.
6-7 8 9 10 11 12 13 14 15-17
IFB_HI IFB_LO VSENSE VCC OVP PWRGOOD OUTA GNDD VIN A1_INP A1_INN A1_OUT A3_INP A3_INN A3_OUT VREF GNDA EN_SS COSC
18-20
Voltage Feedback Op Amp. This op amp is used for voltage feedback from the output, and for loop compensation. Reference Voltage. Decouple with a 0.1F ceramic capacitor. Analog Ground. Return path for low power analog circuitry. This pin should be connected to a low impedance system ground plane to minimize ground loops. Output Enable. A logic LOW on this pin will disable the output. An internal current source allows for open collector control. This pin also doubles as soft start. Oscillator Capacitor. Attach a capacitor from pin 24 to ground to set the oscillator frequency.
21 22 23 24
2
REV. 1.0.0 10/31/01
FAN5035
PRODUCT SPECIFICATION
Absolute Maximum Ratings
Supply Voltage VCC All Other Pins Junction Temperature, TJ Storage Temperature Lead Soldering Temperature, 10 seconds Power Dissipation, PD Thermal Resistance Junction-to-case, JC 13V VCC 150C -65 to 150C 300C 950mW 16C/W
Recommended Operating Conditions
Parameter Supply Voltage VCC VIN Ambient Operating Temperature 0 Conditions Min. 4.75 Typ. 5 3.3 70 Max. 5.25 Units V V C
Electrical Specifications
(VCC = 5V, VOUT = 2.0V, and TA = +25C using circuit in Figure 1, unless otherwise noted.) The * denotes specifications which apply over the full operating temperature range Parameter Voltage Reference Output Voltage Voltage Reference Accuracy Current Feedback Current Feedback Input Range IFB Propagation Delay Oscillator Oscillator Frequency Oscillator Frequency Range Oscillator Frequency TC Oscillator Duty Cycle Oscillator Ramp Amplitude Oscillator Ramp Mean Output Driver OUTA Rise Time OUTA Fall Time OUTA Voltage Low OUTA Voltage High A1 Amplifier A1 Output Current A1 Gain-Bandwidth A1 Open Loop Gain A1 Slew Rate
REV. 1.0.0 10/31/01
Conditions See Table I VID4 = 0 VID4 = 1 * * * * to OUTA COSC=47pF * * * (Voscmax + Voscmin)/2 100pF Load 100pF Load Isink = 20mA Isource = 20mA * * * * * * * * * *
Min. 1.3 -1.2 -1.6 0 180 900 200
Typ.
Max. 3.5 1.2 1.6 VCC-0.5
Units V %
V nsec KHz KHz Hz/C % VPP V nsec nsec V V
250
324 1100 1500
328 45 0.75 1.85 0.9 2.05 49 60 VCC-1.1 1.7 11 50 10 3 15 55 15 55 1.05 2.25 72 80 0.5
mA MHz dB V/sec 3
PRODUCT SPECIFICATION
FAN5035
Electrical Specifications (continued) (VCC = 5V, VOUT = 2.0V, and TA = +25C using circuit in Figure 1, unless otherwise noted.) The * denotes specifications which apply over the full operating temperature range
Parameter A1 Offset Voltage A1 Input Bias Current A1 Common Mode Input Range A1 Output Voltage Swing A3 Amplifier A3 Output Current A3 Gain-Bandwidth A3 Open Loop Gain A3 Slew Rate A3 Offset Voltage A3 Input Bias Current A3 Common Mode Input Range A3 Output Voltage Swing A3 Input Impedance VID Lines D0-4 Pullup to VCC D0-4 Logic High D0-4 Logic Low Protection Over-voltage Protection Over-voltage Hysteresis Over-voltage Output High Over-voltage Current Over-voltage Output Low Over-voltage Input Impedance Short Circuit Threshold Short Circuit Threshold TC VIN Input Impedance VIN UVLO Rising VIN UVLO Falling VIN UVLO Hysteresis VSENSE Input Inpedance VSENSE Propagation Delay VSENSE Propagation Delay VCC UVLO Rising VCC UVLO Falling VCC UVLO Hysteresis to OVP to OUTA Output Low No Load VOVP = 3V VSENSE/VREF * * * * * * * * * * * * * * * * * * 4.0 160 250 2.5 160 28 270 250 250 35 350 340 42 442 400 4.5 48 8 72 10 80 12 60 112 1.2 VCC-0.2 40 50 0.5 12 88 31 72 3.0 115 3 120 % % V mA V K mV V/C K V V mV K nsec nsec V V mV * * * 20 2.1 0.8 25 K V V Rload = 2K to 2.5V INP to Ground * * * * * * * * * 0.25 0.8 9.33 11.67 1.7 11 50 10 3 15 55 15 0.9 340 3 500 VCC-0.98 Voscmid + 0.8 14 mA MHz dB V/sec mV nA V V K Rload = 2K to 2.5V Conditions * * * * -0.1 0.9 Min. Typ. 0.9 340 Max. 3 500 VCC-1.6 VCC-0.95 Units mV nA V V
4
REV. 1.0.0 10/31/01
FAN5035
PRODUCT SPECIFICATION
Electrical Specifications (continued) (VCC = 5V, VOUT = 2.0V, and TA = +25C using circuit in Figure 1, unless otherwise noted.) The * denotes specifications which apply over the full operating temperature range
Parameter Soft Start/Enable Soft Start Charge Current Soft Start Discharge Current Soft Start Pin Voltage Power Good Power Good Output High Power Good Output Low Power Good Sink Current Power Good High Threshold Power Good Low Threshold Power Good Threshold Hysteresis Power Good Propagation Delay Power Good Rise Time Power Good Fall Time VCC Supply VCC Supply Current EN_SS and D0-4 open D0-4 grounded During soft-start * 16 17 22 22 mA VSENSE to PWRGOOD 10K Pullup 10K Pullup VPG = 0.4V VSENSE/VREF VSENSE/VREF * VCC - 0.1 * * * * * 2.0 106 89 1.2 2 60 140 15 2.0 111 94 0.5 V V mA % % % nsec nsec nsec VEN_SS = 1V * * 8 -6 20 10 -5 12 -4 80 A A %VCC Conditions Min. Typ. Max. Units
REV. 1.0.0 10/31/01
5
PRODUCT SPECIFICATION
FAN5035
Table 1. Output Voltage Programming Codes
VID4 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 1 1 1 1 1 1 1 1 1 1 1 1 1 1 1 1
Note: 0 = processor pin is tied to GND. 1 = processor pin is open.
VID3 1 1 1 1 1 1 1 1 0 0 0 0 0 0 0 0 1 1 1 1 1 1 1 1 0 0 0 0 0 0 0 0
VID2 1 1 1 1 0 0 0 0 1 1 1 1 0 0 0 0 1 1 1 1 0 0 0 0 1 1 1 1 0 0 0 0
VID1 1 1 0 0 1 1 0 0 1 1 0 0 1 1 0 0 1 1 0 0 1 1 0 0 1 1 0 0 1 1 0 0
VID0 1 0 1 0 1 0 1 0 1 0 1 0 1 0 1 0 1 0 1 0 1 0 1 0 1 0 1 0 1 0 1 0
Nominal VOUT 1.30V 1.35V 1.40V 1.45V 1.50V 1.55V 1.60V 1.65V 1.70V 1.75V 1.80V 1.85V 1.90V 1.95V 2.00V 2.05V 2.0V 2.1V 2.2V 2.3V 2.4V 2.5V 2.6V 2.7V 2.8V 2.9V 3.0V 3.1V 3.2V 3.3V 3.4V 3.5V
Test Parameters
tR 90% 10% 90% tF OUTA 10%
6
REV. 1.0.0 10/31/01
FAN5035
PRODUCT SPECIFICATION
Mechanical Dimensions
24-Lead TSSOP
Inches Min. A A1 B C D E e H L N ccc Max. Millimeters Min. Max. Notes: Notes 1. Dimensioning and tolerancing per ANSI Y14.5M-1982. 2. "D" and "E" do not include mold flash. Mold flash or protrusions shall not exceed .006 inch (0.15mm). 3. "L" is the length of terminal for soldering to a substrate. 4. Terminal numbers are shown for reference only. 5. Symbol "N" is the maximum number of terminals. 2 2
Symbol
-- .047 .002 .006 .007 .012 .004 .008 .303 .316 .169 .177 .026 BSC .252 BSC .018 .030 24 0 -- 8 .004
-- 1.20 0.05 0.15 0.19 0.30 0.09 0.20 7.70 7.90 4.30 4.50 0.65 BSC 6.40 BSC 0.45 0.75 24 0 -- 8 0.10
3 5
D
E
H
A B e
A1 SEATING PLANE -C- LEAD COPLANARITY ccc C L
C
REV. 1.0.0 10/31/01
7
PRODUCT SPECIFICATION
FAN5035
Ordering Information
Product Number FAN5035MTCX Package 24-pin TSSOP
DISCLAIMER FAIRCHILD SEMICONDUCTOR RESERVES THE RIGHT TO MAKE CHANGES WITHOUT FURTHER NOTICE TO ANY PRODUCTS HEREIN TO IMPROVE RELIABILITY, FUNCTION OR DESIGN. FAIRCHILD DOES NOT ASSUME ANY LIABILITY ARISING OUT OF THE APPLICATION OR USE OF ANY PRODUCT OR CIRCUIT DESCRIBED HEREIN; NEITHER DOES IT CONVEY ANY LICENSE UNDER ITS PATENT RIGHTS, NOR THE RIGHTS OF OTHERS. LIFE SUPPORT POLICY FAIRCHILD'S PRODUCTS ARE NOT AUTHORIZED FOR USE AS CRITICAL COMPONENTS IN LIFE SUPPORT DEVICES OR SYSTEMS WITHOUT THE EXPRESS WRITTEN APPROVAL OF THE PRESIDENT OF FAIRCHILD SEMICONDUCTOR CORPORATION. As used herein: 1. Life support devices or systems are devices or systems which, (a) are intended for surgical implant into the body, or (b) support or sustain life, and (c) whose failure to perform when properly used in accordance with instructions for use provided in the labeling, can be reasonably expected to result in a significant injury of the user. 2. A critical component in any component of a life support device or system whose failure to perform can be reasonably expected to cause the failure of the life support device or system, or to affect its safety or effectiveness.
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10/31/01 0.0m 000 Stock#DS30005035 2001 Fairchild Semiconductor Corporation

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