Philips Semiconductors

Product specification

SA5778

Serial triple gauge driver (STGD)

2

1998 Apr 03

853–2055 19199

DESCRIPTION

The Serial Triple Gauge Driver (STGD), is a single chip air core

driver providing drive to one major gauge, and two minor gauges, for

automotive applications such as Speedometer, Fuel, Temperature,

Tachometer, Volts, and Oil pressure information display. The STGD

operates in conjunction with a microcontroller receiving serial data

inputs, and can provide status back to the microcontroller either

serially or via a status line. The protocol is compatible with the

Philips Single Gauge Driver (SGD) and Dual Gauge Driver (DGD).

The STGD also includes a protected battery supply for external

single Serial Gauge Drivers or Dual Gauge Drivers.

PIN CONFIGURATION

7

821

22

1

2

3

4

5

6

9

10

11

12

13

14

24

23

20

19

18

17

16

15

25

26

27

28

SIN+

RUN

GOE

SwCONTROL

SwBATT1

GND

SwBATT2

COM

C2–

SIN–

COS+

ST

GND

CS

C1–

C1+

C2+

SR01116

GND

GND

GND

GND

GND

GND

COS–

Figure 1.

Pin Configuration

FEATURES

– Sine/Cosine outputs for 360

° operation

– 0.2

° accuracy typical throughout entire range

– 112

° operation

– 0.5

° accuracy typical throughout entire range

– Supports interface from microcontrollers

– Compatible with Philips SGD SA5775A and DGD SA5777A

– Permits the STGD to be wired in series using a common chip

select to additional STGDs, SGDs, and DGDs

– Permits fault status information to be returned to the

microcontroller

Standby Current Operation

– Gauge drivers disabled when supply voltage exceeds specified

operating voltage, protection to 40V.

– Gauge drivers disabled when die temperature exceeds

operating range

– External switch may supply overvoltage protected battery

supply to other devices operating off battery

BLOCK DIAGRAM

CS

GOE

RUN

MINOR GAUGE 1

MAJOR GAUGE

10-BIT SR

10-BIT SR

10-BIT SR

ENABLE

7-BIT

Tan

DAC

7-BIT

Tan

DAC

7–BIT, SINE

/COSINE

DAC

ST

4-BIT STATUS

LATCH

MUX

9-BIT DATA

LATCH

BIAS, TSD

SwBATT,

COMMON

REFERENCE

MUX

MUX

SR01117

9-BIT DATA

LATCH

10-BIT DATA

LATCH

MINOR GAUGE 2

Figure 2.

STGD Internal Block Diagram