The device’s typical operating circuit schematic shown in Figure 5 generates ±6.5V source-driver supplies at 100mA each

and also generates +16V and -7V for gate-driver supplies. The current rating for the gate-driver supplies is 3mA (max)

on each output. The input voltage for the TFT power section is 2.7V to 5.5V. The LED driver is a boost LED driver that

operates from a 4.75V to 18V input and can withstand a 40V load dump. The LED current per string is set at 160mA and

can power two strings with a 34V (max) output voltage. Table 1 lists recommended critical components and Table 2 lists

contact information for the component suppliers.

Figure 5. Typical Operating Circuit Schematic

D1

L1

BATTERY INPUT

FAULT OUTPUT

ENABLE INPUT

BATT

EP

EN

GND

SEQ

DN

DP

PGVDD

IN

DGVEE

DGVDD

FBPG

FBNG

REF

C1

C1

C21

R15

C13

R11

C22

DIM

INPUT

D12

C23

C12

C5

C6

L2

D17

TFT POWER

INPUT

C7

C8

C9

C10

C19

C14

C11

C20

D6-2

D9-2

D10-1

D11-1

D10-2

MAX20070

D11-2

L3

R16

C3

C4

D6-1

D9-1

FLT

LGND

LGND

AGND

LGND

AGND

AGND

AGND

AGND

R9

R10

R12

LGND

DRAIN

PGND

COMP

CS

OVP

ISET

DIM

OUT1

OUT2

LX

FBP

INN

HVINP

POS

NEG

LXN

LGND

TFT POWER

INPUT

R17

TFT POWER

INPUT

R5

R4

R6

R7

R8

LGND

AGND

10μF,

10V

1μF

50V

4.7μF

25V

C2

1μF

50V

1μF

25V

0.1μF,

50V

0.1μF

50V

0.1μF

50V

1μF

25V

16.9kΩ

200kΩ

1μF

25V

0.1μF

0.1μF

0.1μF

50V

50V

50V

150kΩ

845kΩ

20kΩ

C25

50V

0.22μF

4.7μF

25V

4.7μF

4.7μF

4.7μF

25V

25V

25V

0Ω

55kΩ

4.7μF

25V

C17

4.7μF

25V

Q1

EN

EN

7.5kΩ

2.55kΩ

0.04Ω

18.7kΩ

242kΩ

33nF

C29

470pF

CS

CS

C39

220pF

R21

16Ω

1W

Typical Operating Circuit Schematic

MAX20070

Integrated TFT Power Supply and

LED Backlight Driver

www.maximintegrated.com

Maxim Integrated │ 17