11

LTC1429

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 represen-

tation that the interconnection of its circuits as described herein will not infringe on existing patent rights.

The internal resistor values are the same for the fixed

output versions of the LTC1429 as they are for the adjust-

able parts. The output voltage can be trimmed, if desired,

by connecting external resistance from the COMP pin to

OUT or ground to alter the divider ratio. As in the adjustable

parts, the absolute value of the internal resistors may vary

significantly from unit to unit. As a result, the further the

trim shifts the output voltage, the less accurate the output

voltage will be. If a precise output voltage other than one

of the available fixed voltages is required, it’s better to use

an adjustable LTC1429 and use precision external resis-

tors. The internal reference is trimmed at the factory to

within 3.5% of 1.24V. With 1% external resistors, the

output will be within 5.5% of the nominal value, even

under worst case conditions.

The LTC1429 can be internally configured with nonstand-

ard fixed output voltages. For details, contact the Linear

Technology Marketing Department.

2

3

4

5

10

9

13

8

7

11

ADJ

SYNC/SD

R1

R0

OUT

0.1

µF

LTC1429 • TA06

NC

NC

6

14

0.1

µF

0.001

µF

0.22

µF

LTC1429CS

3V

GND

3.3

µF

AT 10mA

–5V Supply Generator

Minimum Parts Count – 4V Generator

1

2

3

4

8

7

6

5

SYNC/SD

REG

OUT

COMP

GND

LTC11429 • TA07

3.3

µF

0.1

µF

5V

LTC1429CS8-4

0.1

µF

3.3V In, – 4.5V Out GaAs FET Bias Generator

2

3

4

5

8

13

12

11

10

9

SYNC/SD

REG

OUT

ADJ

R1

0.1

µF

0.001

µF

0.22

µF

NC

LTC1429 • TA03

3.3

µF

–4.5V BIAS

10k

76

14

0.1

µF

SYNC/SD

3.3V

LTC1429CS

R0

GND

GaAs

TRANSMITTER

P-CHANNEL

POWER SWITCH

5V In, – 4V Out GaAs FET Bias Generator

1

2

3

4

8

7

6

5

SYNC/SD

REG

OUT

COMP

GND

0.001

µF

LTC11429 • TA04

3.3

µF

– 4V BIAS

10k

P-CHANNEL

POWER SWITCH

0.1

µF

SYNC/SD

5V

LTC1429CS8-4

GaAs

TRANSMITTER

0.1

µF