STMICROELECTRONICS L9821

L9821
HIGH SIDE DRIVER
..
.
..
.
25A PEAK OUTPUT CURRENT
RON = 100mΩ
DIAGNOSTIC AND PROTECTION
FUNCTIONS
µP COMPATIBLE
GROUNDED CASE
INRUSH CURRENT LIMITING CIRCUIT
DESCRIPTION
The L9821 High Side Driver realized with Multipower - BCD mixed technology, drives resistive or inductive loads with one side connected to ground.
The input control is TTL compatible and a diagnostic output provides an indication of load (open and
short) and device status (thermal and overvoltage
shutdown).Onchip thermalprotectionand short circuit protection are provided.
MULTIPOWER BCD TECHNOLOGY
Pentawatt
ORDERING NUMBER : L9821
The device is assembled in the Pentawattpackage
with the tab connected to the ground terminal.
BLOCK DIAGRAM
February 1997
1/7
L9821
ABSOLUTE MAXIMUM RATINGS
Symbol
VS
Parameter
Value
50Vdc
Max Forward Voltage
Positive Transient Peak Voltage (dump : τf fall time constant = 100ms,
5ms ≤ trise ≤ 10ms, Rsource ≥ 0.5Ω)
– Resistive Load
– Inductive Load
60V
50V (*)
Reverse Input Voltage
VI
V4
V5
Input Voltage Pin 2 (to GND)
Pin 4 Voltage
Pin 5 Voltage
(to GND)
(to GND)
I1
I2
I4
I5
Pin
Pin
Pin
Pin
PTOT
1
2
4
5
– 0.3Vdc
– 0.3V / + Vs (Vs < 20V)
– 0.3V / + Vs (Vs < 20V)
– 3V / + Vs (Vs < 20V)
Current
Current (forced)
Current (sink)
Current
Internally Limited
0.5mA
10mA
Internally Limited
Power Dissipation
Internally Limited
TJ, TSTG Junction and Storage Temperature Range
– 55°C to + 150°C
* due to the negative voltage at the output during the switching off.
THERMAL DATA
Symbol
R th j-case
Parameter
Thermal Resistance Junction-case
PIN CONNECTION (top view)
2/7
Max
Value
Unit
1.5
°C/W
L9821
PIN FUNCTIONS
condition. This output detects with Tipically 45ms
delay at Tamb = 25°C the following faults :
1. POWER SUPPLY
Supply voltage input. When the supply reaches the
maximum operating voltage (32V) the device is turned off, protecting itself and the load.
Turning off guaranteed for VS > 41V.
-
2. INPUT
TTL compatible input. High level on this pin means
outputcurrentON. Thelow level voltageswitches off
the charge pump, the power stage and the diagnostic output reducing to the minimum value the quiescent current.
Overvoltage condition.
Thermal shutdown.
Short circuit. The powerstagecurrentis internally
limited at 25A.
Open load. The open load condition is detected
with load current < 0.6A.
The diagnostic output is active low. The diagnostic
delay time allows to avoid spurious diagnosys (i.e :
turn ON overcurrent, overvoltage spikes etc.).
-
3. GROUND
This pin must be connected to ground.
5. POWER OUTPUT
The device is provided with short circuit protection
at Vs ≤ 14.4V
4. DIAGNOSTIC FEEDBACK
The diagnostic circuit is active in input high level
ELECTRICAL CHARACTERISTICS (VS = 14.4V; -40°C ≤ Tj ≤ 125°C, unless otherwise specified)
Symbol
Parameter
V OP
Operat. Voltage
R ON
On Resistance
Test Condition
Min.
Typ.
6
Input >2V:Tj = 25°C
Input >2V:Full T range
Unit
32
V
Ω
0.1
0.2
ISC
Short circuit current
25
IDL
Over Current Detection Level
20
IOPD
Open Load Detection Level
Device ON
Output Under Voltage Clamping
Iload <6A Inductive
IOff
Off State Supply Current
Tj = -40 to 35°C
Tj = 35 to 85°C
ION
ON State Supply Current
Tj = 25°C
VIL
Input Low Level
V IH
Input High Level
Vclamp
Max.
-12
A
A
1.2
A
-4
V
100
300
µA
µA
mA
10
0.8
2.0
V
V
Input Current
Vi = Vthreshold
15
µA
ILEAKD
Diagnostic Output Leakage
Voltage
VCC = 5V
Diagnostic Output
10
µA
VSATD
Diagnostic Output Saturation
Voltage
Isink <1.6mA
0.4
V
II
TDd
Diagnostic Delay Time
Tj = 25°C;
45
ms
tdON
Output ON Delay Time
Tj = 25°C
15
µs
tr
Output ON Rise Time
Tj = 25°C
65
µs
Output OFF Delay Time
Tj = 25°C
50
µs
Output OFF Fall Time
Tj = 25°C
100
µs
tdOFF
tf
3/7
L9821
FUNCTIONAL DESCRIPTION
The L9821is a high sidedrive monolithic switch, driven by TTL, CMOS input logic, able to supply resistive or inductive loads up to 6A DC allowing a
current peak of 25A with a RDS(ON) = 0.1. The electronicswitch, in additionto its main function,protects
itself, the power network and the load against load
dump (up to 60V) and overload and it detects short
circuit, open load and overtemperature conditions.
All these functions (logic control and power actuation)are possible on a singlechip thanks to the new
mixed ST MultipowerBCD technologythat allows to
integrate isolated DMOS power transistors in combinationwith Bipolarand CMOS signal structureson
the same chip.
The high side drive connection (series switch between the load and the positive powersource)is particularlysuited in automotiveenvironmentwherethe
electrochemicalcorrosion withstandinghas primary
importance. For this connection the best solution is
a Power MOS N-channel which requires for driving
only a capacitive charge pump completely integrated on the switch chip.
The L9821 is based on a power DMOS series element, a driving circuit with a charge pump, an input
logic interface and on some protectionand fault detection circuits.
The power DMOS transistor has a RDS(ON) = 0.1Ω
(typ. value @ TJ = 25°C, VGS = 10V). The low value
of RDS(ON) is important both to increase the power
transferred to the load and to minimize the power
dissipated in the device.
The charge pump is a capacitivevoltage tripler starting from power supply (car battery), driven by a
500kHz oscillator.
The input interface is based on a circuitry solution
able to guarantee the stability over temperature of
the TTL logic levels and very low quiescent current
in OFF condition.
When the supply reaches the maximum operating
voltage (32V) the device is turned OFF, protecting
itself and the load ; moreoverlocal zener clamps are
provided in some critical points to avoid that VGS of
4/7
any MOS transistor could reach dangerous values
even during 60V load dump transient.
The inrush current limiting is a significant feature of
the L9821. This functionallows to protect the power
supplynetwork and may extend the life of the loads.
For example, in the case of the lamps, the tungsten
wire resistance value in cold condition is about one
tenthof the nominalsteadystateand then the inrush
current during the turn on is statistically one of the
main causes of lamps failures. If the high current
condition persists (e.g. load short circuit) and the
junctiontemperaturerises above150°C,the thermal
protectioncircuit turns off the device preventingany
damage. The current limiting and the thermal shutdown are sufficient to protectthe device againstany
overload becausethe power DMOS has not the second breakdown.
When the L9821 is driven and one of the protections (overtemperature, overvoltage, overload) is
present, a fault detection open drain output turns
on. This output is active also when Iload is lower
than 0.6A detectingthe open load (disconnected or
burned out). The diagnostic output detects fault
conditions with 25ms delay in order to avoid spurious diagnosys (i.e. : turn on overcurrent, overvoltage spikes etc.). In OFF conditions the fault
detection circuits are not active to allow a minimum
quiescent current.
The device can drive unipolar DC motors and solenoids as well becauseit can recirculate an inductive
current when the output voltage goes lower than
Vclamp value (typically - 6.5V in respect to ground).
The possibility to have a start up current is useful
also for DC motors allowing the maximum starting
torque.
TYPICAL APPLICATION OF THE L9821
The L9821 integrated high side driver can be used
to replace an electromechanical relay.
Inductiveload (i.e. solenoids,motors) can be driven
by the L9821. No externalcomponents are required
for the coil current recirculation, because the device
provides this function internally.
L9821
Figure 1.
5/7
L9821
PENTAWATT PACKAGE MECHANICAL DATA
mm
DIM.
MIN.
inch
TYP.
A
C
D
2.4
MAX.
4.8
1.37
2.8
MIN.
0.094
MAX.
0.189
0.054
0.110
D1
E
F
1.2
0.35
0.8
1.35
0.55
1.05
0.047
0.014
0.031
0.053
0.022
0.041
F1
G
G1
1
1.4
0.039
0.126
0.260
0.055
0.142
0.276
3.4
6.8
H2
H3
L
10.4
10.4
10.05
L1
L2
L3
L5
L6
L7
0.134
0.268
0.409
0.409
0.396
17.85
0.703
15.75
21.4
22.5
0.620
0.843
0.886
2.6
15.1
6
M
M1
Dia
TYP.
3
15.8
6.6
0.102
0.594
0.236
0.118
0.622
0.260
4.5
4
0.177
0.157
3.65
3.85
0.144
0.152
E
L
D1
C
D
M
A
M1
L1
L2
G
L7
L6
6/7
F
H2
F1
Dia.
G1
L3
H3
L5
L9821
Information furnished is believed to be accurate and reliable. However, SGS-THOMSON Microelectronics assumes no responsibility for
the consequences of use of such information nor for any infringement of patents or other rights of third parties which may result from its
use. No license is granted by implication or otherwise under any patent or patent rights of SGS-THOMSON Microelectronics. Specification
mentioned in this publication are subject to change without notice. This publication supersedes and replaces all information previously
supplied. SGS-THOMSON Microelectronics products are not authorized for use as critical components in life support devices or systems
without express written approval of SGS-THOMSON Microelectronics.
 1997 SGS-THOMSON Microelectronics – Printed in Italy – All Rights Reserved
SGS-THOMSON Microelectronics GROUP OF COMPANIES
Australia - Brazil - Canada - China - France - Germany - Hong Kong - Italy - Japan - Korea - Malaysia - Malta - Morocco -The Netherlands - Singapore - Spain - Sweden - Switzerland - Taiwan - Thailand - United Kingdom - U.S.A.
7/7