Block diagram and pin description

L9953 / L9953XP

6/38

Doc ID 14278 Rev 4

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

VCC

V

BAT

µC

GN D

Mirro r C o mmo n

M irro r V e rtic a l

M irror H o riz o nta l

Loc k / F o lder

1k

MU X

4

D e fro s te r

PW M 1

OU T 6

OU T 7

1k

1k

1k

1k

1k

* N o te : Value of c apac itor ha s to be c hoos e n c a re fu lly to lim it the VS v o ltage b e lo w abs olute

m a x im u m ra tings in c a s e of a n unex pe c ted free w h ee ling c o n d itio n (e .g . TS D , P O R )

*

* * N o te : R e s is tors b e tw een µC and L99 53 ar e re c o m m ended to lim it c u rre n ts

fo r negativ e v o lta ge tra n s i e n ts at VB AT (e .g . IS O ty pe 1 puls e )

R ev e rs e P o la rit y

P rot e c tion

**

**

**

**

**

**

100µ F