Logic supply voltage - nominally 5V

GROUND

Device Ground. This ground applies for the logic cir-

cuits as well as the power output stages.

RESET

Asynchronous reset for the output stages, the par-

allel latch and the shift register inside the

L9822ESP. This pin is active low and it must not be

left floating. A power on clear function may be im-

nal resistor and to ground with an external capacitor.

CE

Chip Enable. Data is transferred from the shift reg-

isters 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 en-

abled when this pin is low.

SO

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 par-

ticular 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 imple-

ments the diagnostic data supplied by the L9822.

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.

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 fall-

ing edge into the shift register.

OUTPUTS 00-07

Power output pins. The input and output bits corres-

ponding 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.

PIN DESCRIPTION

Symbol

Parameter

Test Conditions

Min.

Typ.

Max.

Unit

Output Clamping Volt.

30

40

V

Out. Clamping Energy

20

mJ

Out. Leakage Current

1

mA

On Resistance

Output Progr. ON

With Fault Reset Disabled

0.55

0.55

0.55

1

1

1

Ω

Ω

Ω

Out. Self Limiting

Current

Output Progr. ON

1.05

A

Turn-on Delay

No Reactive Load

10

µs

Turn-off Delay

No Reactive Load

10

µs

Fault Refer. Voltage

Output Progr. OFF

1.6

2

V

Fault Reset Delay

(after CE L to H

transition)

See fig. 3

75

250

µs

Output OFF Voltage

Output Pin Floating.cOutput Progr. OFF,

1.0

V

L9822E

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