Block diagram and pin description

L9953 / L9953XP

6/38

Doc ID 14278 Rev 3

1

Block diagram and pin description

Figure 1.

Block diagram

Table 2.

Pin definitions and functions

Pin

Symbol

Function

1, 18, 19, 36

GND

Ground:

Reference potential

Important: for the capability of driving the full current at the outputs all

pins of GND must be externally connected.

2, 35

OUT8

Highside driver output 8

The output is built by a highside switch and is intended for resistive

loads, hence the internal reverse diode from GND to the output is

missing. For ESD reason a diode to GND is present but the energy

which can be dissipated is limited. The highside driver is a power

DMOS transistor with an internal parasitic reverse diode from the

output to VS (bulk-drain-diode). The output is over-current and open

load protected.

Important: for the capability of driving the full current at the outputs both

pins of OUT8 must be externally connected.

3

4

5

OUT1

OUT2

OUT3

Half-bridge-output 1,2,3

The output is built by a highside and a lowside switch, which are

internally connected. The output stage of both switches is a power

DMOS transistor. Each driver has an internal parasitic reverse diode

(bulk-drain-diode: highside driver from output to VS, lowside driver from

GND to output). This output is over-current and open load protected.

OU T 1

OU T 2

OU T 3

OU T 4

OU T 5

OU T 8

M

M

M

Ch a rg e

Pu m p

PW M 2 / C M

CS N

CL K

DO

DI

VS

VC C

VC C

V

BAT

µC

GN D

M irro r C o m m o n

M irro r V e rtica l

M irro r H o rizo n ta l

Lo ck / F o ld er

1k

MU X

4

De fro s te r

PW M 1

OU T 6

OU T 7

1k

1k

1k

1k

1k

* N o te : V a lu e o f ca p a cito r h a s to b e ch o o s e n ca re fu lly to lim it th e V S vo lta g e b e lo w a b s o lu te

m a xim u m ra ting s in ca se of a n un exp e cted free w hee lin g co nd itio n (e .g . TS D , P O R )

*

** N o te : R e sisto rs be tw een µ C an d L 995 3 a re re co m m e nd ed to lim it cu rren ts

fo r ne g a tive vo lta g e tra n sien ts a t VBAT (e .g . IS O typ e 1 p u lse )

Rev e rs e P olarity

P rotec tion

**

**

**

**

**

**

100µ F