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LT3796/LT3796-1

3796fa

For more information www.linear.com/3796

TYPICAL APPLICATION

FEATURES DESCRIPTION

100V Constant-Current and

Constant-Voltage Controller

with Dual Current Sense

The LT

3796/LT3796-1 are DC/DC controllers designed to

regulate a constant-current or constant-voltage and are

ideal for driving LEDs. The fixed frequency and current

mode architecture result in stable operation over a wide

range of supply and output voltages. Two ground referred

voltage FB pins serve as the input for several LED protec-

tion features, and also allow the converter to operate as a

constant-voltage source. The LT3796/LT3796-1 feature a

programmable threshold output current sense amplifier

with rail-to-rail common mode range. A separate high

side amplifier is gain configurable with two resistors and

can be used to regulate a second current or a voltage

in combination with one of the FB pins. The PWM input

provides LED dimming ratios of up to 3000:1.

The LT3796-1 is optimized for a second output current

regulation loop that can be enabled/disabled with a PMOS

switch, either to drive a second LED string or to extend

analog dimming range.

Boost LED Driver with Input Current Monitor

APPLICATIONS

3000:1 True Color PWM™ Dimming

Wide Input Voltage Range: 6V to 100V

Current Monitoring Up to 100V

High Side PMOS Disconnect and PWM Switch Driver

Constant-Current and Constant-Voltage Regulation

Dual Current Sense Amplifiers with Reporting

C/10 Detection for Battery and SuperCap Charging

Linear Current Sense Threshold Programming

Short-Circuit Protection

Adjustable Frequency: 100kHz to 1MHz

Frequency Synchronization (LT3796)

Independent Top Gate Enable Pin (LT3796-1)

Programmable Open LED Protection with VMODE Flag

Programmable Undervoltage Lockout with Hysteresis

Soft-Start with Programmable Fault Restart Timer

Available in 28-Lead TSSOP Package

High Power LED, High Voltage LED, Dual String

Battery and SuperCap Chargers

Accurate Current Limited Voltage Regulators

L, LT, LTC, LTM, Linear Technology and the Linear logo are registered trademarks and True

Color PWM is a trademark of Linear Technology Corporation. All other trademarks are the

property of their respective owners. Protected by U.S. Patents, including 7199560, 7321203,

7746300.

Efficiency vs V

(V)

100

30 50

37961 TA01b

10 20

40 60

EFFICIENCY (%)

118k

CSPV

CSN

VMODE

FAULT

VMODE

FAULT

85V LED

400mA

LT3796

37961 TA01a

CTRL

CSOUT

PWM

ISMON

PWM

SYNC

FB2

EN/UVLO

REF

GND

FB1

ISP

ISN

INTV

GATE

SENSE

10nF

22µH

50mΩ

9V TO 60V

100V (TRANSIENT)

4.7µF

31.6k

250kHz

10k

INTV

499k

97.6k

2.2µF

×4

13.7k

15mΩ

620mΩ

40.2k

10nF

100k 100k

CSOUT

INTV

2.2µF

×3

0.1µF

Summary of content (36 pages)

PAGE 1
LT3796/LT3796-1 100V Constant-Current and Constant-Voltage Controller with Dual Current Sense DESCRIPTION FEATURES n n n n n n n n n n n n n n n n 3000:1 True Color PWM™ Dimming Wide Input Voltage Range: 6V to 100V Current Monitoring Up to 100V High Side PMOS Disconnect and PWM Switch Driver Constant-Current and Constant-Voltage Regulation Dual Current Sense Amplifiers with Reporting C/10 Detection for Battery and SuperCap Charging Linear Current Sense Threshold Programming Short-Circuit Protection Adjust
PAGE 2
LT3796/LT3796-1 ABSOLUTE MAXIMUM RATINGS PIN CONFIGURATION (Note 1) VIN, VS.....................................................................100V EN/UVLO..................................................................100V ISP, ISN....................................................................100V TG, GATE...............................................................Note 2 CSP, CSN.................................................................100V VS - CSP, VS - CSN...........................
PAGE 3
LT3796/LT3796-1 ELECTRICAL CHARACTERISTICS The l denotes the specifications which apply over the full operating temperature range, otherwise specifications are at TA = 25°C, VIN = 24V, EN/UVLO = 24V, CTRL = 2V, PWM = 5V, unless otherwise noted. PARAMETER CONDITIONS MIN TYP MAX UNITS VIN Minimum Operating Voltage VIN Tied to INTVCC 6 V VIN Shutdown IQ EN/UVLO = 0V, PWM = 0V EN/UVLO = 1.15V, PWM = 0V 1 12 µA µA VIN Operating IQ (Not Switching) RT = 82.5k to GND, FB1 = 1.5V 2.5 3 mA 2.
PAGE 4
LT3796/LT3796-1 ELECTRICAL CHARACTERISTICS The l denotes the specifications which apply over the full operating temperature range, otherwise specifications are at TA = 25°C, VIN = 24V, EN/UVLO = 24V, CTRL = 2V, PWM = 5V, unless otherwise noted. PARAMETER CONDITIONS MIN TYP MAX UNITS Current Sense Amplifier (CSA) Power Supply Voltage Range (VS) l 3 100 V CSA Input Voltage Common Mode Range (VCSP and VCSN) l 2.
PAGE 5
LT3796/LT3796-1 ELECTRICAL CHARACTERISTICS The l denotes the specifications which apply over the full operating temperature range, otherwise specifications are at TA = 25°C, VIN = 24V, EN/UVLO = 24V, CTRL = 2V, PWM = 5V, unless otherwise noted. PARAMETER CONDITIONS MIN TYP MAX UNITS Gate Driver tr NMOS GATE Driver Output Rise Time CL = 3300pF, 10% to 90% 20 tf NMOS GATE Driver Output Fall Time CL = 3300pF, 10% to 90% 18 NMOS GATE Output Low (VOL) ns ns 0.
PAGE 6
LT3796/LT3796-1 TYPICAL PERFORMANCE CHARACTERISTICS 253 200 150 100 50 0 0 0.2 0.6 0.8 VCTRL (V) 0.4 1.0 1.2 254 251 250 249 248 251 250 249 248 0 20 60 40 VISP (V) 246 –50 –25 100 80 0 25 50 75 100 125 150 TEMPERATURE (°C) 37961 G03 37961 G02 V(ISP-ISN) Threshold at CTRL = 0.6V vs Temperature V(ISP-ISN) Threshold vs FB Voltage 128 300 127 250 1.27 VFB vs Temperature FB1 126 125 124 123 122 –50 –25 0 25 50 75 150 1.24 50 1.2 1.15 TEMPERATURE (°C) 1.
PAGE 7
LT3796/LT3796-1 TYPICAL PERFORMANCE CHARACTERISTICS VREF vs VIN 2.05 100 IREF = 0µA TA = 25°C, unless otherwise noted. Switching Frequency vs Temperature RT vs Switching Frequency 440 2.02 RT (kΩ) VREF (V) 2.03 2.01 10 2.00 1.99 420 410 400 390 380 1.98 1.97 370 0 20 60 40 80 1 100 VIN (V) 360 –50 –25 0 100 200 300 400 500 600 700 800 900 1000 SWITCHING FREQUENCY (kHz) 37961 G09 2.5 450 50 75 100 125 150 37961 G11 Quiescent Current vs VIN 2000 VISMON vs V(ISP-ISN) 1800 2.
PAGE 8
LT3796/LT3796-1 TYPICAL PERFORMANCE CHARACTERISTICS SENSE Current Limit Threshold vs Duty Cycle 120 110 105 0 20 40 60 80 VIN = 24V 100 80 60 40 20 0 100 100 INTVCC CURRENT LIMIT (mA) INTVCC CURRENT LIMIT (mA) SENSE THRESHOLD (mV) 115 0 20 60 40 80 60 50 –50 –25 100 8 1600 7 1400 3 2 1 125°C 80 25°C 800 0°C 600 0 100 7.7 7.6 7.5 400 7.4 –55°C –40°C 0 5 VIN (V) 10 15 7.
PAGE 9
LT3796/LT3796-1 TYPICAL PERFORMANCE CHARACTERISTICS Top Gate (PMOS) Rise/Fall Time vs Capacitance NMOS Gate Rise/Fall Time vs Capacitance Current Sense Amplifier Gain vs Frequency 30 160 800 25 140 700 120 600 15 TIME (ns) 10 5 0 –5 100 RISE TIME 80 60 FALL TIME 40 –10 VS = 48V, RIN = 1k –15 ROUT = 10k, VSENSE = 100mV (NOTE 5) –20 0.1 1 10 100 0.01 TIME (ns) 20 GAIN (dB) TA = 25°C, unless otherwise noted.
PAGE 10
LT3796/LT3796-1 PIN FUNCTIONS ISP (Pin 1): Connection Point for the Positive Terminal of the Current Feedback Resistor (RLED). Also serves as positive rail for TG pin driver. ISN (Pin 2): Connection Point for the Negative Terminal of the Current Feedback Resistor (RLED). TG (Pin 3): Top Gate Driver Output. An inverted PWM signal drives series PMOS device between VISP and (VISP – 7V) if VISP > 7V. An internal 7V clamp protects the PMOS gate by limiting VGS. Leave TG unconnected if not used.
PAGE 11
LT3796/LT3796-1 PIN FUNCTIONS SYNC (Pin 13) LT3796: The SYNC pin is used to synchronize the internal oscillator to an external logic level signal. If SYNC is used, the RT resistor should be chosen to program an internal switching frequency 20% slower than the SYNC pulse frequency. Gate turn-on occurs a fixed delay after the rising edge of SYNC. Use a 50% duty cycle waveform to drive this pin. If not used, tie this pin to GND. TGEN (Pin 13) LT3796-1: Top Gate Driver Enable Pin.
PAGE 12
LT3796/LT3796-1 BLOCK DIAGRAM EN/UVLO FB1 A1 – VC SHDN ISP-7V VIN 1.25V + 1.25V 1.5V VLED X1 7.7V INTVCC 10µA AT FB1 = 1.25V LT3796-1 ONLY SCILMB A5 – A4 SHORT-CIRCUIT DETECT – LDO + gm 3µA ISMON PWM ISP A2 – + 1.22V TGEN (LT3796-1 ONLY) TGOFFB 2.5V + 10µA ISP + 100mV –+ X4 ISN – – + + 1.1V CTRL FB2 gm EAMP FAULTB + R A7 A6 – 10µA AT A6+ = A6– S PWM COMPARATOR ILIM A8 – + – + 1.25V 5.5V 113mV A9 A9 gm VS GATE DRIVER Q 10µA AT FB2 = 1.
PAGE 13
LT3796/LT3796-1 OPERATION The LT3796/LT3796-1 are constant-frequency, current mode controllers with a low side NMOS gate driver. The operation of the LT3796/LT3796-1 is best understood by referring to the Block Diagram.
PAGE 14
LT3796/LT3796-1 APPLICATIONS INFORMATION INTVCC Regulator Bypassing and Operation The INTVCC pin requires a capacitor for stable operation and to store the charge for the large GATE switching currents. Choose a 10V rated low ESR, X7R or X5R ceramic capacitor for best performance. A 4.7μF ceramic capacitor is adequate for many applications. Place the capacitor close to the IC to minimize the trace length to the INTVCC pin and also to the IC ground. is to allow the user to program the rising hysteresis.
PAGE 15
LT3796/LT3796-1 APPLICATIONS INFORMATION longer varies with CTRL. The typical V(ISP-ISN) threshold vs CTRL is listed in the Table 1. Table 1. V(ISP-ISN) Threshold vs CTRL VCTRL (V) V(ISP-ISN) (mV) 1 225 regulation. FB2 does not have this extra comparator. The output voltage can be set by selecting the values of R3 and R4 (see Figure 2) according to the following equation: VOUT =1.25 • 1.05 236 1.1 244.5 1.15 248.5 1.2 250 R3+R4 R4 VOUT LT3796/LT3796-1 R3 FB1 When CTRL is higher than 1.
PAGE 16
LT3796/LT3796-1 APPLICATIONS INFORMATION + RSENSE R9 VOUT LT3796/ LT3796-1 – Q1 LED ARRAY FB1 37961 F03b R10 Figure 3b. Feedback Resistor Connection for Buck Mode or Buck-Boost Mode LED Driver Using External PNP recommended to limit the transient short-circuit current. With the PNP helper, the short-circuit current can be limited to 2A, whereas the short-circuit current can reach to 20A without the PNP helper as shown in Figure 5 and Figure 6 respectively.
PAGE 17
LT3796/LT3796-1 APPLICATIONS INFORMATION A second method uses the PWM pin to modulate the LED current between zero and full current to achieve a precisely programmed average current, without the possibility of color shift that occurs at low current in LEDs. To make PWM dimming more accurate, the switch demand current is stored on the VC node during the quiescent phase when PWM is low. This feature minimizes recovery time when the PWM signal goes high.
PAGE 18
LT3796/LT3796-1 APPLICATIONS INFORMATION Table 2. Typical Switching Frequency vs RT Value (1% Resistor) fosc(kHz) RT(kΩ) 1000 6.65 900 7.50 800 8.87 700 10.2 600 12.4 500 15.4 400 19.6 300 26.1 200 39.2 100 82.5 respectively. The following equations express the minimum/ maximum duty cycle: Min Duty Cycle = minimum on-time • switching frequency Max Duty Cycle = 1 – minimum off-time • switching frequency 350 300 250 TIME (ns) RT resistor value see Table 2.
PAGE 19
LT3796/LT3796-1 APPLICATIONS INFORMATION For buck applications, filter components, RIN2(OPT) and COPT, are recommended to be placed close to LT3796/ LT3796-1 to suppress the substantial transient signal or noise at across CSN and CSP pins. For boost and buckboost applications, RIN2(OPT) and COPT are not required. +VSNS– RSNS TJ = TA + [VIN • (IQ + fSW • QG) •θJA] where TA is the ambient temperature, IQ is the VIN operating current of the part (2.
PAGE 20
LT3796/LT3796-1 APPLICATIONS INFORMATION require a lower value capacitor than a buck mode converter. Assuming that a 100mV input voltage ripple is acceptable, the required capacitor value for a boost converter can be estimated as follows (TSW = 1/fOSC): V 1µF CIN (µF) =ILED(A) • LED • TSW (µs) • VIN A • µs • 2.8 Therefore, a 2.2µF capacitor is an appropriate selection for a 400kHz boost regulator with 12V input, 48V output and 500mA load.
PAGE 21
LT3796/LT3796-1 APPLICATIONS INFORMATION in Table 4. The MOSFETs used in the application circuits in this data sheet have been found to work well with the LT3796/LT3796-1. Consult factory applications for other recommended MOSFETs. Table 4. MOSFET Manufacturers VENDOR WEB Vishay Siliconix www.vishay.com Fairchild www.fairchildsemi.com International Rectifier www.irf.com Infineon www.infineon.
PAGE 22
LT3796/LT3796-1 APPLICATIONS INFORMATION of approximately 20mV magnitude. The following equations are useful to estimate the inductor value (TSW = 1/fOSC): LBUCK = TSW •RSENSE • VLED (V IN – VLED ) V IN • 0.02V LBUCK, BOOST = TSW •RSENSE • VLED • V IN (VLED +V IN) • 0.02V Soft-Start Capacitor Selection For many applications, it is important to minimize the inrush current at start-up. The built-in soft-start circuit significantly reduces the start-up current spike and output voltage overshoot.
PAGE 23
LT3796/LT3796-1 APPLICATIONS INFORMATION Board Layout The high speed operation of the LT3796/LT3796-1 demands careful attention to board layout and component placement. The exposed pad of the package is the GND terminal of the IC and is also important for thermal management of the IC. It is crucial to achieve a good electrical and thermal contact between the exposed pad and the ground plane of the board.
PAGE 24
LT3796/LT3796-1 APPLICATIONS INFORMATION X VIN VIA VIN RSNS1 X VIAS TO GROUND PLANE X ROUTING ON THE 2nd LAYER C3 VIA FROM ISP R6 VIA FROM ISN X 1 VIA FROM TG X VIA FROM OUT R7 ISMON R8 CC RC R2 X VIA FROM VIN R1 VREF C6 C4 27 X 3 26 C1 R5 L1 4 25 X 5 24 6 23 X 7 22 8 21 9 20 10 19 11 C1 28 LT3796 X 2 12 RT C1 VIA FROM VIN R3 R4 VIA FROM VIN C5 INTVCC VIA X X 1 18 29 2 17 SYNC 13 16 PWM 14 15 GATE VIA 3 8 7 M1 6 X 4 R9 R10 X VIA FROM INTVCC
PAGE 25
LT3796/LT3796-1 TYPICAL APPLICATIONS Boost LED Driver with Output Short Circuit Protection and LED Current Monitor VIN 9V TO 60V 100V (TRANSIENT) C1 2.2µF ×3 R1 1M OPTIONAL INPUT CURRENT REPORTING R3 499k VS GATE R9 100k RSNS 15mΩ LT3796 PWM FB1 SYNC SYNC ISP ISMON FAULT INTVCC VMODE VREF R11 OPTIONAL FOR FAULT LATCHOFF R11 402k (OPT) RLED 620mΩ M2 TG VMODE SS FB2 RC 10k C6 0.1µF D2 C5 4.7µF RT VC INTVCC 85V LED RT 31.
PAGE 26
LT3796/LT3796-1 TYPICAL APPLICATIONS Buck Mode LED Driver with Open LED Flag and LED Current Reporting VIN 24V TO 80V RLED 100mΩ LED+ M2 2.5A R3 49.9k R1 1M VS VIN R2 61.9k ISN CSP VREF CSN L1 33µH R6 59k FB1 FB2 LED CURRENT REPORTING C5 0.1µF SENSE INTVCC R8 100k M1 GATE ISMON C2 4.7µF ×2 25V R5 1M CSOUT LT3796 PWM 18V LED TG EN/UVLO CTRL PWM ISP R4 49.9k D1 C1 2.2µF ×3 100V RSNS 15mΩ R9 100k FAULT GND FAULT VMODE VMODE INTVCC VC RT RC 10k CC 4.
PAGE 27
LT3796/LT3796-1 TYPICAL APPLICATIONS SEPIC LED Driver Using FB2 for Input Overvoltage Protection C1 2.2µF ×3 100V R1 953k VIN VREF OPTIONAL INPUT CURRENT REPORTING CSOUT PWM M1 C2 10µF ×3 35V R10 909k R11 40.2k SENSE RSNS 15mΩ LT3796 FB2 R7 40.2k CSN GATE CTRL C3 0.1µF CSP L1B EN/UVLO R5 100k R3 20k VS D1 • R6 2k R4 511k R2 75k L1A 22µH RSNS1 50mΩ • IIN VIN 8V TO 60V C6 2.2µF 100V GND CSOUT FB1 PWM ISP UP TO 1A RLED 250mΩ ISN ISMON LED CURRENT REPORTING TG C7 0.
PAGE 28
LT3796/LT3796-1 TYPICAL APPLICATIONS SEPIC Sealed Lead Acid (SLA) Battery Charger RSNS1 50mΩ IIN D2 15V C1 4.7µF 50V R1 10k R2 806k R6 2k R4 357k VIN R3 20k CSN VS CSP R11 10k NTC + BAT RSNS 15mΩ LT3796 FB2 GND FB1 CSOUT CSOUT C3 10nF R12 30.1k VCHARGE = 14.6V VFLOAT = 13.5V AT 25°C SENSE VREF CTRL OPTIONAL INPUT CURRENT REPORTING BAT R13 93.1k M1 GATE OUT RSNS2 C2 250mΩ 10µF L1B EN/UVLO R5 100k D1 • M2 L1A 33µH • VIN 8V TO 40V 100V (TRANSIENT) C6 2.2µF 100V R7 40.
PAGE 29
LT3796/LT3796-1 TYPICAL APPLICATIONS 28VIN to 28V SuperCap Charger with Input Current Limit and Charge Done Flag RSNS1 150mΩ 1.33A MAX R1 20k VIN VS L1B CSP CSN EN/UVLO OUTPUT CURRENT REPORTING ISMON VREF RSNS 33mΩ LT3796 GND CSOUT FB1 FB2 ISP R6 100k INTVCC C6 4.7µF FAULT CHGDONE 1.67A MAX SUPERCAP TG FAULT R9 24.9k ISN INTVCC R7 100k C2 4.7µF ×2 50V R8 536k RSNS2 150mΩ SS C4 0.
PAGE 30
LT3796/LT3796-1 TYPICAL APPLICATIONS SEPIC Converter with RWIRE Compensation and Output Current Limit C2 10µF L1A 22µH OUT RSNS1 250mΩ D1 • VIN 12V 1:1 • C1 10µF M1 C3 10µF L1B + RWIRE C4 100µF 25V VLOAD 12V, 1A CURRENT LIMIT RSNS 33mΩ VIN C8 0.1µF GATE GND ISP ISMON ISN PWM VREF SENSE EN/UVLO LT3796 SYNC R3 154k SS VS CTRL VREF INTVCC R7 100k R2 38.3k CSN FB2 C5 0.1µF R1 38.3k C7 1µF OUT CSP R6 100k R4 287k CSOUT FAULT FAULT VMODE FB1 VMODE TG VC RT RT 19.
PAGE 31
LT3796/LT3796-1 TYPICAL APPLICATIONS Solar Panel Driven SLA Battery Charger with Maximum Power Point Tracking WÜRTH SOLAR PANEL VOC = 37.5V VMPP = 28V BAT RSNS1 250mΩ • M2 D1 D2 15V 1:1 C1 4.7µF 50V • R4 301k INTVCC C2 10µF L1B R1 10k R10 30.1k R9 10k NTC VCHARGE = 14.6V VFLOAT = 13.5V AT 25°C + BAT R5 137k R2 475k VIN VS CSN CSP R3 20k SENSE CTRL CSOUT C3 0.1µF M1 GATE EN/UVLO RSNS 15mΩ LT3796 CSOUT R6 100k R11 93.
PAGE 32
LT3796/LT3796-1 TYPICAL APPLICATIONS Boost LED Driver for Twin LEDs with Detection and Protection for Faulty LED VIN 8V TO 20V L1 22µH D1 C1 2.2µF ×3 RSNS 15mΩ R1 499k EN/UVLO R2 97.6k LED STRING 1 CURRENT REPORTING FB1 VS C2 0.1µF ISMON LT3796-1 FAULT INTVCC FAULT VMODE M2 TG TGEN INTVCC C5 4.7µF VMODE VC SS SS C3 0.
PAGE 33
LT3796/LT3796-1 TYPICAL APPLICATIONS SEPIC LED Driver with 100:1 Analog Dimming C1 2.2µF ×3 M1: INFINEON BSC16ON1ONS3-G M2: VISHAY SILICONIX Si7461DP M3: ZETEX ZXM6IN02F L1: COILTRONICS DR Q 127-220 D1: DIODES INC PDS5100 D2: NXP PMEG6010CEJ LED: CREE XLAMP XR-E M1 3 R4 113k 2 R2 97.6k C3 0.1µF 8 1 LTC1541 OP AMP – C2 0.1µF 5 6 – LTC1541 COMP RLED1 270mΩ FB2 ISN VREF INTVCC CTRL FAULT R11 200k R10 7.87k 7 M3 M2 TG PWM C4 0.1µF R9 30.1k C5 0.1µF RLED2 3.
PAGE 34
LT3796/LT3796-1 PACKAGE DESCRIPTION Please refer to http://www.linear.com/designtools/packaging/ for the most recent package drawings. FE Package 28-Lead Plastic TSSOP (4.4mm) (Reference LTC DWG # 05-08-1663 Rev J) Exposed Pad Variation EB 9.60 – 9.80* (.378 – .386) 4.75 (.187) 4.75 (.187) 28 27 26 2524 23 22 21 20 1918 17 16 15 6.60 ±0.10 4.50 ±0.10 2.74 (.108) SEE NOTE 4 0.45 ±0.05 EXPOSED PAD HEAT SINK ON BOTTOM OF PACKAGE 6.40 2.74 (.252) (.108) BSC 1.05 ±0.10 0.
PAGE 35
LT3796/LT3796-1 REVISION HISTORY REV DATE DESCRIPTION A 1/13 Added LT3796-1 option PAGE NUMBER 1 to 36 3796fa Information furnished by Linear Technology Corporation is believed to be accurate and reliable. However, no responsibility is assumed for its use. Linear Technology Corporation makes no representation that the interconnection of its circuits as described herein will not infringe on existing patent rights. For more information www.linear.
PAGE 36
LT3796/LT3796-1 TYPICAL APPLICATION Buck-Boost Mode LED Driver with Open LED Clamp and Output Voltage Limit L1 68µH R4 715k C1 2.2µF ×2 R5 20k R6 200k VIN R2 187k CSN PWM INTVCC R10 100k C4 0.1µF VS RSNS 33mΩ LT3796 FB2 PWM ISP 100 R7 1M PWM = VREF 95 R8 13.3k GND FB1 Efficiency vs VIN M1 SENSE CTRL RLED 1Ω ISMON ISN R9 100k FAULT VIN GATE CSOUT R3 249k CSP EN/UVLO VREF C3 4.