Ds1870 ldmos rf power-amplifier bias controller, Advanced application, Package information – Rainbow Electronics DS1870 User Manual

Page 28: Sda and scl pullup resistors

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DS1870

LDMOS RF Power-Amplifier Bias
Controller

Maxim cannot assume responsibility for use of any circuitry other than circuitry entirely embodied in a Maxim product. No circuit patent licenses are
implied. Maxim reserves the right to change the circuitry and specifications without notice at any time.

28

____________________Maxim Integrated Products, 120 San Gabriel Drive, Sunnyvale, CA 94086 408-737-7600

© 2004 Maxim Integrated Products

Printed USA

is a registered trademark of Maxim Integrated Products.

DALLAS is a registered trademark of Dallas Semiconductor Corporation.

SDA and SCL Pullup Resistors

SDA is an open-collector output on the DS1870 that
requires a pullup resistor to realize high logic levels. A
master using either an open-collector output with a
pullup resistor or a push-pull output driver can be used
for SCL. Pullup resistor values should be chosen to
ensure that the rise and fall times listed in the AC elec-
trical characteristics are within specification.

Advanced Application

A circuit showing the implementaion of current sensing
using the DS1870 is shown under “Advanced
Application”.

SDA

SCL

A2

A1

A0

FAULT

V

CC

GND

5V

5V REFERENCE

R

POT1

49.9k

(1%)

LOW

PASS

FILTER

R

POT2

R

S2

R

S1

4.22k

(1%)

VD

ID1

ID2

RF

POWER

AMP

RF

IN

RF

OUT

W

1

L

1

W

2

H

COM

L

2

N.C.

N.C.

4.7kΩ

3 PLACES

NOTES:
1) IN THIS CONFIGURATION, THE VOLTAGE RANGE OF W

1

AND W

2

IS

3V-5V. THIS RANGE CAN BE EXTENDED USING EXTERNAL RESISTORS.
2) ONE MAX6156B CAN BE USED WITH MULTIPLE DS1870s.

DS1870

MAX6165B

MAX4080

LOW

PASS

FILTER

MAX4080

28V

Advanced Application with Current Sense

Chip Information

TRANSISTOR COUNT: 52,353

SUBSTRATE CONNECTED TO GROUND

Package Information

For the latest package outline information, go to
www.maxim-ic.com/DallasPackInfo.

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