Datasheet
L9822E Pin description
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2.1 Pin description
Table 2. Pin function
PowerSO20
pin #
Multiwatt15
pin #
Name Function
1, 10, 11, 20 8 GND
Device ground.
This ground applies for the logic circuits as well as the
power output stages.
29SO
Serial output.
This pin is the serial output from the shift register and it is
tri-stated when CE is high. A high for a data bit on this pin
indicates that the particular output is high. A low on this
pin for a data bit indicates that the output is low.
Comparing the serial output bits with the previous serial
input bits the external microcontroller implements the
diagnostic data supplied by the L9822E.
310V
CC
Logic supply voltage - nominally 5V.
4 11 RESET
Asynchronous reset for the output stages, the parallel
latch and the shift register inside the
L9822E. This pin is
active low and it must not be left floating. A power on clear
function may be implemented connecting this pin to VCC
with an external resistor and to ground with an external
capacitor.
5-8, 13-16 1-4, 12-15
OUTPUT
1-7
Power output pins.
The input and output bits corresponding to 07 are sent
and received first via the SPI bus and 00 is the last. The
outputs are provided with current limiting and voltage
sense functions for fault indication and protection. The
nominal load current for these outputs is 500mA, but the
current limiting is set to a minimum of 1.05A.
The outputs also have on board clamps set at about 36V
for recirculation of inductive load current.
9,12 - N.C. Pins not connected.
17 5 CE
Chip enable.
Data is transferred from the shift registers to the outputs
on the rising edge of this signal. The falling edge of this
signal sets the shift register with the output voltage sense
bits coming from the output stages. The output driver for
the SO pin is enabled when this pin is low.
18 6 SCLK
Serial clock.
This pin clocks the shift register. New SO data will appear
on every rising edge of this pin and new SI data will be
latched on every SCLK’s falling edge into the shift
register.
19 7 SI
Serial input.
This pin is the serial data input. A high on this pin will
program a particular output to be OFF, while a low will
turn it ON.