LINEAR TECHNOLOGY LTC3783 Technical data

FEATURES

V

PWMIN

5V/DIV

I

L

2.5A/DIV

I

LED

0.5A/DIV

V

OUT

0.2V/DIV

AC COUPLED

1µs/DIV

3783 TA01b

LTC3783

PWM LED Driver and Boost,

Flyback and SEPIC Controller

U

DESCRIPTIO

■

True Color PWMTM Delivers Constant Color with
3000:1 Dimming Ratio

■

Fully Integrated Load FET Driver for PWM Dimming
Control of High Power LEDs

■

100:1 Dimming from Analog Inputs

■

Wide FB Voltage Range: 0V to 1.23V

■

Constant Current or Constant Voltage Regulation

■

Low Shutdown Current: IQ = 20µA

■

1% 1.23V Internal Voltage Reference

■

2% RUN Pin Threshold with 100mV Hysteresis

■

Programmable Operating Frequency (20kHz to
1MHz) with One External Resistor

■

Synchronizable to an External Clock Up to 1.3f

■

Internal 7V Low Dropout Voltage Regulator

■

Programmable Output Overvoltage Protection

■

Programmable Soft-Start

■

Can be Used in a No R

■

16-Lead DFN and TSSOP Packages

SENSE

TM

Mode for VDS < 36V

OSC

U

APPLICATIO S

■

High Voltage LED Arrays

■

Telecom Power Supplies

■

42V Automotive Systems

■

24V Industrial Controls

■

IP Phone Power Supplies

, LT, LTC and LTM are registered trademarks of Linear Technology Corporation.
True Color PWM and No R
All other trademarks are the property of their respective owners.

are trademarks of Linear Technology Corporation.

SENSE

The LTC®3783 is a current mode LED driver and boost,
flyback and SEPIC controller that drives both an N-channel
power MOSFET and an N-channel load PWM switch.
When using an external load switch, the PWMIN input not
only drives PWMOUT, but also enables controller GATE
switching and error amplifier operation, allowing the con­troller to store load current information while PWMIN is
low. This feature (patent pending) provides extremely fast,
true PWM load switching with no transient overvoltage or
undervoltage issues; LED dimming ratios of 3000:1 can be
achieved digitally, avoiding the color shift normally asso­ciated with LED current dimming. The FBP pin allows
analog dimming of load current, further increasing the
effective dimming ratio by 100:1 over PWM alone.

In applications where output load current must be re­turned to V

, optional constant current/constant voltage

IN

regulation controls either output (or input) current or
output voltage and provides a limit for the other. I

LIM

provides a 10:1 analog dimming ratio.

For low- to medium-power applications, No R

SENSE

mode
can utilize the power MOSFET’s on-resistance to eliminate
the current-sense resistor, thereby maximizing efficiency.

The IC’s operating frequency can be set with an external
resistor over a 20kHz to 1MHz range and can be synchro­nized to an external clock using the SYNC pin.

The LTC3783 is available in the 16-lead DFN and TSSOP
packages.

TYPICAL APPLICATIO

350mA PWM LED Boost Application

V

IN

6V TO 16V

OF LEDs)

(< TOTAL V

F

0.1µF

10µF

10k 6k

1M

RUN
PWMIN
I

TH

SS

105k

V

REF

FBP
FBN
FREQ
SYNC

M1, M2: SILICONIX Si4470EY

LTC3783

PWMOUT

OV/FB

GATE

SENSE

INTV

GND

V

IN

I

LIM

CC

U

10µF

2.2µH

×2

ZETEX ZLLS1000

237k

M1

4.7µF

0.05Ω

12.4k 0.3Ω

*LUMILEDS LHXL-BW02

LED*
STRING

M2

3783 TA01a

C

10µF

GND

V

OUT

<25V

OUT

Typical Waveforms

3783fa

1

LTC3783

WWWU

ABSOLUTE AXI U RATI GS

(Note 1)

VIN, SENSE, FBP, FBN Voltages ................ – 0.3V to 42V

INTV
INTV

Voltage ........................................... –0.3V to 9V

CC

Output Current ........................................ 75mA

CC

GATE Output Current ................................ 50mA (RMS)

PWMOUT Output Current ......................... 25mA (RMS)

Ouput Current................................................ 1mA

V

REF

GATE, PWMOUT Voltages ..... –0.3V to (V

, I

I

TH

, SS Voltages .............................. – 0.3V to 2.7V

LIM

INTVCC

+ 0.3V)

RUN, SYNC, PWMIN Voltages .................... – 0.3V to 7V

UU

W

PACKAGE/ORDER I FOR ATIO

TOP VIEW

FBN

1

FBP

2

I

3

LIM

V

4

REF

FREQ

SYNC

PWMIN

PWMOUT

16-LEAD (5mm × 4mm) PLASTIC DFN

T

JMAX

EXPOSED PAD (PIN 17) IS GND

MUST BE SOLDERED TO PCB

17

5

6

7

8

DHD PACKAGE

= 125°C, θJA = 43°C/ W

16

RUN

15

I

TH

OV/FB

14

SS

13

SENSE

12

V

11

IN

INTV

10

CC

GATE

9

ORDER PART

NUMBER

LTC3783EDHD

DHD PART MARKING

3783

FREQ, V

, OV/FB Voltages .....................– 0.3V to 1.5V

REF

Operating Temperature Range

(Note 2) .................................................. – 40°C to 85°C

Junction Temperature (Note 3)............ – 40°C to 125°C

Storage Temperature Range

DFN Package ................................... –65°C to 125°C

TSSOP Package ............................... – 65°C to 150°C

Lead Temperature (Soldering, 10sec)

TSSOP Package ............................................... 300°C

TOP VIEW

1

FBN

2

FBP

3

I

LIM

4

V

REF

5

FREQ

6

SYNC

7

PWMIN

PWMOUT

8

FE PACKAGE

16-LEAD PLASTIC TSSOP

T

= 125°C, θJA = 38°C/ W

JMAX

EXPOSED PAD (PIN 17) IS GND

MUST BE SOLDERED TO PCB

RUN

16

I

15

TH

OV/FB

14

SS

13

17

SENSE

12

V

11

IN

INTV

10

CC

GATE

9

ORDER PART

NUMBER

LTC3783EFE

Order Options Tape and Reel: Add #TR
Lead Free: Add #PBF Lead Free Tape and Reel: Add #TRPBF

Lead Free Part Marking: http://www.linear.com/leadfree/

Consult LTC Marketing for parts specified with wider operating temperature ranges.

ELECTRICAL CHARACTERISTICS

The ● denotes specifications which apply over the full operating temperature range, otherwise specifications are TA = 25°C.
V

= 12V, V

IN

SYMBOL PARAMETER CONDITIONS MIN TYP MAX UNITS
Main Control Loop/Whole System

V

IN

I

Q

+

V

RUN

–

V

RUN

V

RUN(HYST)

= 1.5V, V

RUN

SYNC

= 0V, V

FBP

= V

, RT = 20k, unless otherwise specified.

REF

Input Voltage Range 336V
Input Voltage Supply Current (Note 4)

Continuous Mode V
Shutdown Mode V

= 1.5V, V

OV/FB

= 0V 20 µA

RUN

= 0.75V 1.5 mA

ITH

Rising RUN Input Threshold Voltage 1.348 V
Falling RUN Input Threshold Voltage 1.223 1.248 1.273 V
RUN Pin Input Threshold Hysteresis 100 mV

3783fa

2

LTC3783

ELECTRICAL CHARACTERISTICS

The ● denotes specifications which apply over the full operating temperature range, otherwise specifications are TA = 25°C.
V

= 12V, V

IN

SYMBOL PARAMETER CONDITIONS MIN TYP MAX UNITS

I

RUN

V

SENSE(MAX)

I

SENSE(ON)

I

SENSE(OFF)

I

SS

Voltage/Temperature Reference

V

REF

I

REF

∆V

/∆VINReference Voltage Line Regulation 3V ≤ VIN ≤ 36V 0.002 0.02 %/V

REF

∆V

/∆I

REF

T

MAX

T

HYST

Error Amplifier

I

OV/FB

∆V

OV/FB(OV)

V

OV/FB(FB)

I

, I

FBP

FBN

V

– V

FBP

FBN

g

m

A

VOL

Oscillator

f

OSC

D

MAX

f

SYNC/fOSC

t

SYNC(MIN)

t

SYNC(MAX)

V

IH(SYNC)

V

HYST(SYNC)

R

SYNC

t

ON(MIN)

= 1.5V, V

RUN

SYNC

= 0V, V

FBP

= V

, RT = 20k, unless otherwise specified.

REF

RUN Pin Input Current 5nA
Maximum Current Sense Threshold 125 150 180 mV
SENSE Pin Current (GATE High) V
SENSE Pin Current (GATE Low) V

= 0V 70 µA

SENSE

= 36V 0.2 µA

SENSE

Soft-Start Pin Output Current VSS = 0V –50 µA

Reference Voltage 1.218 1.230 1.242 V

●

1.212 1.248 V

Max Reference Pin Output Current 0.5 mA

Reference Voltage Load Regulation 0mA ≤ I

REF

≤ 0.5mA 0.2 1.0 %/mA

REF

Overtemperature SD Threshold 165 °C
Rising

Overtemperature Hysteresis 25 °C

OV/FB Pin Input Current 18 60 nA
OV/FB Overvoltage Lockout Threshold V
OV/FB Pin Regulation Voltage 2.5V < V
Error Amplifier Input Current 0V ≤ V

2.5V < V

Error Amplifier Offset Voltage 0V ≤ V
(Note 5) 2.5V < V

2.5V < V

Error Amplifier Transconductance V

2.5V < V

OV/FB(OV)

FBP

FBP

≤ V

FBP

– V

OV/FB(NOM)

< 36V 1.212 1.230 1.248 V

FBP

≤ V

REF

< 36V 50 µA

FBP

≤ V

REF

≤ 36V (V

FBP

≤ 36V (V

FBP

REF

< 36V 14 mmho

FBP

in %, V

FBP

≤ V

REF

7%

–0.4 µA

–3 3 mV

= V

ILIM
ILIM

) 100 mV

REF

= 0.123V) 10 mV

1.7 mmho

Error Amplifier Open-Loop Gain 500 V/V

Oscillator Frequency R

= 20kΩ 250 300 350 kHz

FREQ

Oscillator Frequency Range 20 1000 kHz
Maximum Duty Cycle 85 90 97 %
Recommended Max SYNC Freq Ratio f
SYNC Minimum Input Pulse Width V
SYNC Maximum Input Pulse Width V

= 300kHz (Note 6) 1.25 1.3

OSC

= 0V to 5V 25 ns

SYNC

= 0V to 5V 0.8/f

SYNC

OSC

ns
SYNC Input Voltage High Level 1.2 V
SYNC Input Voltage Hysteresis 0.5 V
SYNC Input Pull-Down Resistance 100 kΩ
Minimum On-time With Sense Resistor, 10mV Overdrive 170 ns

No R

Mode 300 ns

SENSE

3783fa

3

LTC3783

ELECTRICAL CHARACTERISTICS

The ● denotes specifications which apply over the full operating temperature range, otherwise specifications are TJ = 25°C.

= 12V, V

V

IN

SYMBOL PARAMETER CONDITIONS MIN TYP MAX UNITS
Low Dropout Regulator

V

INTVCC

UVLO INTVCC Undervoltage Lockout Rising INTV

∆V

INTVCC

∆V

IN

∆V

LDO(LOAD)

V

DROPOUT

I

INTVCC(SD)

GATE/PWMOUT Drivers

t

r(GATE)

t

f(GATE)

I

PK(GATE,RISE)

I

PK(GATE,FALL)

V

PWMIN

R

PWMIN

t

r(PWMOUT)

t

f(PWMOUT)

I

PK(PWMOUT,RISE)

I

PK(PWMOUT,FALL)

= 1.5V, V

RUN

INTVCC Regulator Output Voltage V

Thresholds Falling INTV

SYNC

= 0V, V

FBP

= V

, RT = 20k, unless otherwise specified.

REF

= 1.5V

OV/FB

CC
CC

●

6.5 7 7.5 V

2.3 2.5 V

1.8 2.1 V

Hysteresis 0.2 V

INTVCC Line Regulation 12V ≤ VIN ≤ 36V 2 6 mV/V

INTVCC Load Regulation 0 ≤ I
INTVCC Dropout Voltage VIN = 7V, I
Bootstrap Mode INTVCC Supply V

Current in Shutdown V

SENSE
SENSE

≤ 10mA –1 –0.1 %

INTVCC

= 10mA 300 500 mV

INTVCC

= 0V 25 µA
= 7V 15 µA

GATE Driver Output Rise Time CL = 3300pF (Note 7) 15 ns
GATE Driver Output Fall Time CL = 3300pF (Note 7) 8 ns
GATE Driver Peak Current Sourcing V
GATE Driver Peak Current Sinking V

= 0V 0.5 A

GATE

= 7V 1 A

GATE

PWMIN Pin Input Threshold Voltages Rising PWMIN 1.6 V

Falling PWMIN 0.8 V
Hysteresis 0.8 V

PWMIN Input Pull-Up Resistance 100 kΩ
PWMOUT Driver Output Rise Time CL = 3300pF (Note 7) 30 ns
PWMOUT Driver Output Fall Time CL = 3300pF (Note 7) 16 ns
PWMOUT Driver Peak Current Sourcing V
PWMOUT Driver Peak Current Sinking V

= 0V 0.25 A

PWMOUT

= 7V 0.50 A

PWMOUT

Note 1: Stresses beyond those listed under Absolute Maximum Ratings
may cause permanent damage to the device. Exposure to any Absolute
Maximum Rating condition for extended periods may affect device
reliability and lifetime.

Note 2: The LTC3783E is guaranteed to meet performance specifications
from 0°C to 85°C junction temperature. Specifications over the – 40°C to
85°C operating temperature range are assured by design, characterization
and correlation with statistical process controls.

Note 3: T
dissipation P

is calculated from the ambient temperature TA and power

J

according to the following formula:

D

T

= TA + (PD • 43°C/W) for the DFN

J

T

= TA + (PD • 38°C/W) for the TSSOP

J

Note 4: The dynamic input supply current is higher due to power MOSFET

• f

gate charging (Q
Note 5: The LTC3783 is tested in a feedback loop which servos V

= V

V

FBP

(0.3V ≤ V

with the ITH pin forced to the midpoint of its voltage range

VREF

≤ 1.2V; midpoint = 0.75V).

ITH

). See Operation section.

G

OSC

FBN

to

Note 6: In a synchronized application, the internal slope compensation is
increased by 25%. Synchronizing to a significantly higher ratio will reduce
the effective amount of slope compensation, which could result in sub­harmonic oscillation for duty cycles greater than 50%

Note 7: Rise and fall times are measured at 10% and 90% levels.

3783fa

4

UW

I

REF

(mA)

0

V

REF

(V)

1.231

1.233

1.235

4

3783 G03

1.229

1.227

1.225
1

2

3

5

VIN = 12V

VIN = 2.5V

TYPICAL PERFOR A CE CHARACTERISTICS

V

1.25

vs Temperature V

REF

1.235

Line Regulation V

REF

LTC3783

TA = 25°C unless otherwise specified

Load Regulation

REF

1.20

1.15

(V)

REF

V

1.10

1.05

1.00

1.6

1.4

1.2

1.0

0.8

(mA)

Q

I

0.6

0.4

0.2

0

–50

I

–75

0 50 100

TEMPERATURE (°C)

3783 G01

vs Temperature (PWMIN Low) Dynamic IQ vs Frequency

Q

–25 25 125

TEMPERATURE (°C)

75

3783 G04

150

175

1.233

1.231

(V)

REF

V

1.229

1.227

1.225
0

10

IQ vs VIN (PWMIN Low)

2.0

1.9

1.8

1.7

1.6

1.5

(mA)

Q

I

1.4

1.3

1.2

1.1

0

0

10 30

VIN (V)

20

VIN (V)

20

30

40

3783 G02

30

CL = 3300pF

= 1.3mA + QG • f

I

Q(TOT)

25

20

(mA)

Q

15

10

DYNAMIC I

5

0

50

40

3783 G05

0

0.5 1
FREQUENCY (MHz)

1.5

3783 G06

1.6

1.5

1.4

1.3

1.2

1.1

1.0

0.9

RUN THRESHOLDS (V)

0.8

0.7

0.6

RUN Thresholds vs V

RUN HIGH

RUN LOW

0

10

20

VIN (V)

IN

RUN Thresholds vs Temperature RT vs Frequency

1.40

1.38

1.36

1.34

1.32

1.30

1.28

RUN THRESHOLDS (V)

1.26

1.24

30

40

3783 G07

1.22
–50

0

RUN HIGH

RUN LOW

50

TEMPERATURE (°C)

100

150

3783 G08

1000

100

(kΩ)

T

R

10

1

1 100 1000 10000

10

FREQUENCY (kHz)

3783 G09

3783fa

5

LTC3783

UW

TYPICAL PERFOR A CE CHARACTERISTICS

TA = 25°C unless otherwise specified

Frequency vs Temperature Maximum V

350

340

330

320

310

300

290

FREQUENCY (kHz)

280

270

260

250

–50

INTV

CC

7.00

6.95

6.90

6.85

(V)

CC

6.80

INTV

6.75

6.70

6.55

6.50

0.02 0.04 0.06 0.08

0

0

50

TEMPERATURE (°C)

100

150

3783 G10

Load Regulation INTVCC Line Regulation

0.10 0.12 0.14 0.16

I

(mA)

INTVCC

3783 G13

(V)

SENSE

V

7.05

7.00

6.95

6.90

6.85

(V)

CC

6.80

INTV

6.75

6.70

6.65

6.60

6.55

160

158

156

154

152

150

148

146

144

142

140

–50

0

SENSE

0

TEMPERATURE (°C)

10

20

VIN (V)

vs Temperature

50

100

30

40

3783 G11

3783 G14

150

50

I

vs Temperature

SENSE

75

74

73

72

71

(µA)

70

SENSE

69

I

68

67

66

65

–50

INTV

CC

Over Temperature

(V)

CC

INTV

7.0

6.8

6.6

6.4

6.2

6.0

5.8

5.6

5.4

5.2

5.0

–50°C, –25°C, 0°C

0

0

50

TEMPERATURE (°C)

Load Regulation

25°C

75°C

100°C

125°C

150°C

50

I

INTVCC

100

(mA)

100

150

3783 G12

50°C

150

3783 G15

INTV
vs Temperature

7.20

7.15

7.10

(V)

CC

7.05

INTV

7.00

6.95

6.90
5

6

Line Regulation

CC

25°C

1510 20 25 3530 40

VIN (V)

150°C

–50°C

3783 G16

Soft-Start Current

I

SS

vs Temperature

50.0

49.8

49.6

49.4

49.2

49.0

48.8

48.6

48.4

SOFT-START CURRENT (µA)

48.2

48.0

47.8
–50

0

50

TEMPERATURE (°C)

100

3783 G17

150

Gate Rise/Fall Time
vs Capacitance

80

70

60

50

40

TIME (ns)

30

20

10

0

0

GATE TR

5

GATE TF

10

CAPACITANCE (nF)

15

20

3783 G18

3783fa

LTC3783

U

UU

PI FU CTIO S

FBN (Pin 1): Error Amplifier Inverting Input/Negative
Current Sense Pin. In voltage mode (V
pin senses feedback voltage from either the external
resistor divider across V

for output voltage regula-

OUT

tion, or the grounded sense resistor under the load for
output current regulation. In constant current/constant
voltage mode (V

> 2.5V), connect this pin to the

FBP

negative side of the current-regulating resistor. Nominal
voltage for this pin in regulation is either V
100mV) for V

= 1.23V, depending on operational

ILIM

mode (voltage or constant current/constant voltage) set
by the voltage at V

FBP

.

FBP (Pin 2): Error Amplifier Noninverting Input/Positive
Current Sense Pin. This pin voltage determines the control
loop’s feedback mode (voltage or constant current/con­stant voltage), the threshold of which is approximately 2V.
In voltage mode (V

FBP

≤ V

), this pin represents the

REF

desired voltage which the regulated loop will cause FBN to
follow. In constant current/constant voltage mode (V

2.5V), connect this pin to the positive side of the load
current-sensing resistor. The acceptable input ranges for
this pin are 0V to 1.23V (voltage mode) and 2.5V to 36V
(constant current/constant voltage mode).

(Pin 3): Current Limit Pin. Sets current sense resistor

I

LIM

offset voltage (V
regulation (i.e., when V
100mV when V
with V

. Nominal voltage range for this pin is 0.1V to

ILIM

– V

FBP

= 1.23V and decreases proportionally

ILIM

) in constant current mode

FBN

> 2.5V). Offset voltage is

FBP

1.23V.

V

(Pin 4): Reference Voltage Pin. Provides a buffered

REF

version of the internal bandgap voltage, which can be
connected to FBP either directly or with attenuation.
Nominal voltage for this pin is 1.23V. This pin should never
be bypassed by a capacitor to GND. Instead, a 10k resistor
to GND should be used to lower pin impedance in noisy
systems.

FREQ (Pin 5): A resistor from the FREQ pin to ground
programs the operating frequency of the chip. The nomi­nal voltage at the FREQ pin is 0.615V.

SYNC (Pin 6): This input allows for synchronizing the
operating frequency to an external clock and has an
internal 100k pull-down resistor.

FBP

≤ V

FBP

VREF

or (V

), this

FBP

>

FBP

–

PWMIN (Pin 7): PWM Gate Driver Input. Internal 100k
pull-up resistor. While PWMIN is low, PWMOUT is low,
GATE stops switching and the external I
disconnected, saving the I

TH

state.

network is

TH

PWMOUT (Pin 8): PWM Gate Driver Output. Used for
constant current dimming (LED load) or for output discon­nect (step-up power supply).

GATE (Pin 9): Main Gate Driver Output for the Boost
Converter.

INTVCC (Pin 10): Internal 7V Regulator Output. The main
and PWM gate drivers and control circuits are powered
from this voltage. Decouple this pin locally to the IC
ground with a minimum of 4.7µF low ESR ceramic
capacitor.

VIN (Pin 11): Main Supply Pin. Must be closely decoupled
to ground.

SENSE (Pin 12): Current Sense Input for the Control
Loop. Connect this pin to the drain of the main power
MOSFET for V

sensing and highest efficiency for V

DS

SENSE

≤ 36V. Alternatively, the SENSE pin may be connected to
a resistor in the source of the main power MOSFET.
Internal leading-edge blanking is provided for both sens­ing methods.

SS (Pin 13): Soft-Start Pin. Provides a 50µA pull-up
current, enabled and reset by RUN, which charges an
optional external capacitor. This voltage ramp translates
into a corresponding current limit ramp through the main
MOSFET.

OV/FB (Pin 14): Overvoltage Pin/Voltage Feedback Pin. In
voltage mode (V

FBP

≤ V

), this input, connected to V

REF

OUT

through a resistor network, sets the output voltage at
which GATE switching is disabled in order to prevent an
overvoltage situation. Nominal threshold voltage for the
OV pin is 1.32V (V
current/voltage mode (V

+ 7%) with 20mV hysteresis. In

REF

> 2.5V), this pin senses V

FBP

OUT

through a resistor divider and brings the loop into voltage
regulation such that pin voltage approaches V

= 1.23V,

REF

provided the loop is not regulating the load current (e.g.,
[V

FBP

– V

] < 100mV for I

FBN

= 1.23V).

LIM

3783fa

7

LTC3783

U

UU

PI FU CTIO S

ITH (Pin 15): Error Amplifier Output/Compensation Pin. The
current comparator input threshold increases with this
control voltage, which is the output of the g

type error

m

amplifier. Nominal voltage range for this pin is 0V to 1.40V.

RUN (Pin 16): The RUN pin provides the user with an
accurate means for sensing the input voltage and pro­gramming the start-up threshold for the converter. The

W

BLOCK DIAGRA

SLOPE

COMP

FREQ

5

SYNC

6

OSCV-TO-I

falling RUN pin threshold is nominally 1.248V and the
comparator has 100mV hysteresis for noise immunity.
When the RUN pin is grounded, the IC is shut down and the
V

supply current is kept to a low value (20µA typ).

IN

Exposed Pad (Pin 17): Ground Pin. Solder to PCB ground
for electrical contact and rated thermal performance.

V

REF

GND

GATE

4

17

9

CLK

BIAS

S

Q0.615V

R

SS_RESET

V

REF

LOGIC

3

2

1

14

13

15

7

10

I

LIM

FBP

FBN

OV/FB

SS

I

TH

PWMIN

INTV

1.9V

CC

IVMODE

–
+

EA

A

–
–

+

V

REF

OV/FB

1

S

+

OV

V

–

REF

0.2V

TEMP

SENSOR

(165°C)

+

OT

SLEEP

ITRIP

+

SENSE

12

–

–

+

0

–

LDO

V

REF

2.23V

50µA

IMAX

V-TO-I

EN

+

UV

–

BIAS AND
START-UP

+
–

PWMOUT

+
–

0.15V

V

REF

RUN

V

8

16

IN

11

8

3738 BD

3783fa