SA5777A Datasheet, PDF (3/12 Pages) NXP Semiconductors – Dual air-core gauge driver

Philips Semiconductors
Dual air-core gauge driver
Product specification
SA5777A
BLOCK DIAGRAM
V_BB
7 + – BIT
DAC
8
7 + – BIT
DAC
8
MUX
MUX
OE
V_BB
C2+
V_BB/2
C2–
COM
C1+
C1–
CS
V_CC
D_IN
S_CLK
9-BIT LATCH
10-BIT
SHIFT REGISTER
9-BIT LATCH
10-BIT
SHIFT REGISTER
Figure 2. Block diagram
FAULT
ST
DETECTION
D_OUT
SL00461
Table 1. SA5777A Pin Descriptions for the N Package (Dual In-Line)
Pin # Name
Function
1.
C1– Negative output connection to the TAN coil of meter #1.
2.
C1+ Positive output connection to the TAN coil of meter #1.
3.
A_GND Ground for V_BB supply. Pins 3, 12 and 13 should be connected on the circuit board.
4.
V_BB Analog supply. Nominally 13.5 V.
5.
DATA_OUT Serial data output. Output of the internal shift register. When a new data word is shifted in, the old word is shifted out the
DATA_OUT pin. DATA_OUT output is always active.
6.
DATA_IN Serial data input. A new data word is serially shifted into the part on the rising edge of S_CLK. The data is shifted in MSB
first, gauge 1 first.
7.
V_CC 5 V logic supply. The internal latches and registers are set to zero on the rising edge of this signal.
8.
OE
Output drivers are turned off when this input is low.
9.
S_CLK
Serial clock input. Data is loaded into the part on the rising edge of S_CLK. Data is shifted out of DATA_OUT on the falling
edge of S_CLK.
10.
CS
Active high chip select input. When CS is high, the part is enabled to receive a new serial input word. The high-to-low
transition of CS loads the new 20-bit word into the DAC registers and updates the output.
ST
Status output. This is an open drain output and goes low when the coil output buffers (C1+, C1–, C2+, C2–, COM) have
11.
been disabled. The coil outputs may be disabled due to shorted outputs, over-temperature conditions, power-on reset,
or by the output enable (OE) pin. Multiple status outputs , ST, may be wire OR’ed together.
12.
D_GND Ground for V_CC supply. Connect to Pins 3 and 13.
13.
A_GND Ground for V_BB supply. Connect to Pins 3 and 12.
14.
COM Output drive for biased coils. This output will be 1/2 of V_BB.
15.
C2– Negative output connection to the TAN coil of meter #2.
16.
C2+ Positive output connection to the TAN coil of meter #2.
1999 Sep 20
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