STMICROELECTRONICS L9903TR

L9903
MOTOR BRIDGE CONTROLLER
1
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FEATURES
Figure 1. Package
OPERATING SUPPLY VOLTAGE 8V TO 20V,
OVERVOLTAGE MAX. 40V
OPERATING SUPPLY VOLTAGE 6V WITH
IMPLEMENTED STEPUP CONVERTER
QUIESCENT CURRENT IN STANDBY MODE
LESS THAN 50µA
ISO 9141 COMPATIBLE INTERFACE
CHARGE PUMP FOR DRIVING A POWER
MOS AS REVERSE BATTERY PROTECTION
PWM OPERATION FREQUENCY UP TO
30KHZ
PROGRAMMABLE CROSS CONDUCTION
PROTECTION TIME
OVERVOLTAGE, UNDERVOLTAGE, SHORT
CIRCUIT AND THERMAL PROTECTION
REAL TIME DIAGNOSTIC
SO20
Table 1. Order Codes
Part Number
Package
L9903
SO20
L9903TR
Tape & Reel
2
DESCRIPTION
Control circuit for power MOS bridge driver in automotive applications with ISO 9141bus interface.
Figure 2. Block Diagram
VS
10
ST
1
R CP
Reference
BIAS
+
VCC
Charge
pump
= V
STH
f ST
VCC
EN
2
4
REN
DIR
CB1
12
GH1
14
S1
Thermal shutdown
Control Logic
DG
CP
13
Overvoltage
Undervoltage
RDG
11
5
R DIR
R S1
V S1TH =
19
GL1
R GL1
18
GL2
R GL2
VCC
17
R PWM
PWM
R S2
V S2TH =
PR
6
Timer
ISO-Interface
RX
8
15
GH2
16
CB2
9
7
R RX
VCC
TX
K
= 0.5 • V
VS
R TX
I KH
20
October 2005
S2
3
GND
REV. 4
1/17
L9903
Table 2. Pin Function
N°
Pin
1
ST
2
DG
3
PWM
Description
Open Drain Switch for Stepup converter
Open drain diagnostic output
PWM input for H-bridge control
4
EN
Enable input
5
DIR
Direction select input for H-bridge control
6
PR
Programmable cross conduction protection time
7
RX
ISO 9141 interface, receiver output
8
TX
ISO 9141 interface, transmitter input
9
K
10
VS
ISO 9141 Interface, bidirectional communication K-line
Supply voltage
11
CP
Charge pump for driving a power MOS as reverse battery protection
12
GH1
Gate driver for power MOS highside switch in halfbridge 1
13
CB1
External bootstrap capacitor
14
S1
Source/drain of halfbridge 1
15
GH2
16
CB2
External bootstrap capacitor
17
S2
Source/drain of halfbridge 2
18
GL2
Gate driver for power MOS lowside switch in halfbridge 2
19
GL1
Gate driver for power MOS lowside switch in halfbridge 1
20
GND
Ground
Gate driver for power MOS highside switch in halfbridge 2
Figure 3. Pin Connection (Top view)
ST
1
20
GND
DG
2
19
GL1
PWM
3
18
GL2
EN
4
17
S2
DIR
5
16
CB2
PR
6
15
GH2
RX
7
14
S1
TX
8
13
CB1
K
9
12
GH1
10
11
CP
VS
SO20
2/17
L9903
Table 3. Absolute Maximum Ratings
Symbol
Parameter
Value
VCB1 , VCB2 Bootstrap voltage
ICB1 , ICB2
Bootstrap current
VCP
Charge pump voltage
ICP
Charge pump current
VDIR ,VEN Logic input voltage
,VPWM ,VTX
Unit
-0.3 to 40
V
-100
mA
-0.3 to 40
V
-1
mA
-0.3 to 7
V
±1
mA
IDIR ,IEN
,IPWM ,ITX
Logic input current
VDG ,VRX
Logic output voltage
-0.3 to 7
V
IDG ,IRX
Logic output current
-1
mA
-0.3 to VSX + 10
V
VGH1, VGH2 Gate driver voltage
IGH1 , IGH2
Gate driver current
VGL1 , VGL2 Gate driver voltage
IGL1 , IGL2
Gate driver current
-1
mA
-0.3 to 10
V
-10
mA
VK
K-line voltage
-20 to VS
V
VPR
Programming input voltage
-0.3 to 7
V
IPR
Programming input current
-1
mA
VS1 , VS2
Source/drain voltage
-2 to VVS + 2
V
IS1 , IS2
Source/drain current
-10
mA
VST
Output voltage
IST
Step up output current
VVSDC
VVSP
IVS
DC supply voltage
Pulse supply voltage (T < 500ms)
DC supply current
-0.3 to 40
V
-1
mA
-0.3 to 27
V
40
V
-100
mA
For externally applied voltages or currents exceeding these limits damage of the device may occur!
All pins of the IC are protected against ESD. The verification is performed according to MIL883C, human body
model with R=1.5kΩ, C=100pF and discharge voltage ±2kV, corresponding to a maximum discharge energy of
0.2mJ.
Table 4. Thermal Data
Symbol
TJ
Parameter
Operating junction temperature
TJSD
Junction temperature thermal shutdown threshold
TJSDH
Junction thermal shutdown hysteresis
Rth j-amb
Thermal resistance junction to ambient
1)
Value
Unit
-40 to 150
°C
min 150
°C
typ 15
°C
85
°C/W
1. see application note 110 for SO packages.
.
3/17
L9903
Table 5. Electrical Characteristcs
(8V < VVS < 20V, VEN = HIGH, -40°C ≤ TJ ≤ 150°C, unless otherwise specified. The voltages are refered to
GND and currents are assumed positive, when current flows into the pin
Symbol
Parameter
Test Condition
Min.
Typ.
Max.
Unit
20
22
24
V
Supply (VS)
VVS OVH
Overvoltage disable HIGH
threshold
VVS OVh
Overvoltage threshold hysteresis 2)
VVS UVH
Undervoltage disable HIGH
threshold
VVS UVh
Undervoltage threshold
hysteresis 2)
1.6
6
V
7
0.66
IVSL
Supply current
VEN = 0 ; VVS = 13.5V; TJ< 85°C
IVSH
Supply current, pwm-mode
VVS= 13.5V; VEN= HIGH;
VDIR= LOW; S1 = S2 = GND
V
V
50
µA
8.1
13
mA
5.8
10
mA
fPWM = 20kHz; CCBX = 0.1µF;
CGLX = 4.7nF; CGHX = 4.7nF;
RPR = 10kΩ; CPR = 150pF
IVSD
Supply current, dc-mode
VVS= 13.5V; VEN= HIGH;
VDIR= LOW; S1 = S2 = GND
VPWM = LOW; CGHX = 4.7nF
RPR = 10kΩ; CPR = 150pF
Enable input (EN)
VENL
Low level
VENH
High level
VENh
Hysteresis threshold 2)
REN
Input pull down resistance
1.5
3.5
1
VEN = 5V
16
V
V
50
V
100
kΩ
1.5
V
H-bridge control inputs (DIR, PWM)
VDIRL
VPWML
Input low level
VDIRH
VPWMH
Input high level
VDIRh
VPWMh
Input threshold hysteresis 2)
RDIR
RPWM
Internal pull up resistance
to internal VCC 3)
3.5
V
1
VDIR = 0; VPWM = 0
16
50
V
100
kΩ
0.6
V
kΩ
DIAGNOSTIC output (DG)
VDG
Output drop
IDG = 1mA
RDG
Internal pull up resistance
to internal VCC 3)
VDG = 0V
10
20
40
2
2.2
Programmable cross conduction protection 4)
NPR
Threshold voltage ratio VPRH/
VPRL
RPR = 10kΩ
1.8
IPR
Current capability
VPR = 2V
-0.5
mA
ISO interface, transmission input (TX)
VTXL
4/17
Input low level
1.5
V
L9903
Table 5. Electrical Characteristcs (continued)
(8V < VVS < 20V, VEN = HIGH, -40°C ≤ TJ ≤ 150°C, unless otherwise specified. The voltages are refered to
GND and currents are assumed positive, when current flows into the pin
Symbol
Parameter
VTXH
Input high level
VTXh
Input hysteresis voltage 2)
RTX
Internal pull up resistance to
internal VCC 3)
Test Condition
Min.
Typ.
Max.
3.5
V
1
VTX = 0
10
4.5
Unit
20
V
40
kΩ
5.5
V
10
20
kΩ
90
Ω
ISO interface, receiver output (RX)
VRXL
Output voltage high stage
TX = HIGH; IRX = 0; VK = VVS
RRX
Internal pull up resistance
to internal VCC 3)
TX = HIGH;
VRX = 0V
RRXON
ON resistance to ground
TX = LOW;
IRX = 1mA
40
tRXH
Output high delay time
Fig. 1
0.5
µs
tRXL
Output low delay time
0.5
µs
5
ISO interface, K-line (K)
VKL
Input low level
-20V
0.45 ·
VVS
VKH
Input high level
0.55 ·
VVS
VVS
VKh
Input hysteresis voltage 2)
IKH
Input current
VTX = HIGH
RKON
ON resistance to ground
VTX = LOW; IK=10mA
IKSC
Short circuit current
VTX = LOW
0.025·
VVS
Transmission frequency
fK
-5
10
40
60
0.8V
25
µA
30
Ω
130
100
mA
kHz
2. not tested in production: guaranteed by design and verified in characterization
3. Internal VVCC is 4.5V ... 5.5V
4. see page 18 for calculation of programmable cross conduction protection time
tKr
Rise time
2
VVS = 13.5V; Fig. 1
External loads at K-line:
RK = 510Ω pull up
to VVS
6
µs
CK = 2.2nF to GND
tKf
Fall time
2
6
µs
tKH
Switch high delay time
4
17
µs
tKL
Switch low delay time
4
17
µs
tSH
Short circuit detection time
10
40
µs
VVS
+7V
VVS
+10V
VVS
+10V
VVS
+14V
VVS
+14V
VVS
+14V
VVS = 13.5V;
TX = LOW
VK > 0.55 · VVS
Charge pump
VCP
Charge pump voltage
VVS = 8V
VVS = 13.5V
VVS = 20V
5/17
L9903
Table 5. Electrical Characteristcs (continued)
(8V < VVS < 20V, VEN = HIGH, -40°C ≤ TJ ≤ 150°C, unless otherwise specified. The voltages are refered to
GND and currents are assumed positive, when current flows into the pin
Symbol
Parameter
Test Condition
Min.
Typ.
-50
-75
ICP
Charging current
VCP= VVS + 8V
VVS = 13.5V
tCP
Charging time 2)
VCP= VVS + 8V
VVS = 13.5V
CCP = 10nF
fCP
Charge pump frequency
VVS = 13.5V
250
7.5
10
10
Max.
Unit
µA
1.2
4
ms
500
750
kHz
14
14
14
V
V
V
10
Ω
20
Ω
10
20
Ω
Ω
Drivers for external highside power MOS
VCB1
VCB2
Bootstrap voltage
VVS = 8V; ICBX = 0; VSX = 0
VVS =13.5V; ICBX = 0; VSX = 0
VVS = 20V; ICBX = 0; VSX = 0
RGH1L
RGH2L
ON-resistance of SINK stage
VCBX = 8V; VSX = 0
IGHX = 50mA; TJ = 25°C
VCBX = 8V; VSX = 0
IGHX = 50mA; TJ = 125°C
RGH1H
RGH2H
ON-resistance of SOURCE stage
IGHX = -50mA; TJ = 25°C
IGHX = -50mA; TJ = 125°C
VGH1H
VGH2H
Gate ON voltage (SOURCE)
VVS= VSX = 8V; IGHX = 0;
CCBX = 0.1µF
VVS
+6.5V
VVS
+14V
VVS = VSX = 13.5V; IGHX = 0;
CCBX = 0.1µF
VVS
+10V
VVS
+14V
VVS = VSX = 20V; IGHX = 0;
CCBX = 0.1µF
VVS
+10V
VVS
+14V
RGH1
RGH2
RS1
RS2
Gate discharge resistance
EN = LOW
Sink resistance
10
100
kΩ
10
100
kΩ
Drivers for external lowside power MOS
RGL1L
RGL2L
ON-resistance of SINK stage
IGLX = 50mA; TJ = 25°C
IGLX = 50mA; TJ = 125°C
10
20
Ω
Ω
RGL1H,
RGL2H
ON-resistance of SOURCE stage
IGLX = -50mA; TJ = 25°C
IGLX = -50mA; TJ = 125°C
10
20
Ω
Ω
VGL1H,
VGL2H
Gate ON voltage (SOURCE)
VVS = 8V; IGLX = 0
VVS = 13.5V; IGLX = 0
VVS = 20V; IGLX = 0
Gate discharge resistance
EN = LOW
RGL1
RGL2
7V
10V
10V
10
VVS
VVS
14V
100
kΩ
2. not tested in production: guaranteed by design and verified in characterization
Timing of the drivers
tGH1LH
tGH2LH
Propagation delay time
Fig. 2
VVS = 13.5V
VS1 = VS2 =0
CCBX = 0.1µF
RPR= 10kW
6/17
500
ns
L9903
Table 5. Electrical Characteristcs (continued)
(8V < VVS < 20V, VEN = HIGH, -40°C ≤ TJ ≤ 150°C, unless otherwise specified. The voltages are refered to
GND and currents are assumed positive, when current flows into the pin
Symbol
Parameter
tGH1LH
tGH2LH
Propagation delay time including
cross conduction protection time
tCCP
tGH1HL
tGH2HL
Propagation delay time
tGL1LH
tGL2LH
Propagation delay time
tGL1LH
tGL2LH
Propagation delay time including
cross conduction protection time
tCCP
tGL1HL
tGL2HL
Propagation delay time
Test Condition
Fig. 2
VVS = 13.5V
VS1 = VS2 =0
CCBX = 0.1µF
Min.
Typ.
Max.
Unit
0.7
1
1.3
µs
500
ns
500
ns
1.3
µs
500
ns
1
µs
1
µs
1
µs
1
µs
CPR= 150pF;
RPR= 10kΩ;
5)
Fig. 2
VVS = 13.5V
VS1 = VS2 =0
CCBX = 0.1µF
RPR= 10kΩ
Fig. 2
VVS = 13.5V
VS1 = VS2 =0
CCBX = 0.1µF
0.7
1
CPR= 150pF;
RPR= 10kΩ;
5)
tGH1r
tGH2r
Rise time
tGH1f
tGH2f
Fall time
tGL1r
tGL2r
Rise time
tGL1f
tGL2f
Fall time
Fig. 2
VVS = 13.5V
VS1 = VS2 =0
CCBX = 0.1µF
CGHX = 4.7nF
CGLX = 4.7nF
RPR= 10kΩ;
Short Circuit Detection
VS1TH
VS2TH
tSCd
Threshold voltage
4
Detection time
Step up converter (ST)
5
15
µs
10
V
2
V
20
Ω
149
kHz
(5.2V ≤ VVS < 10V)
VSTH
ST disable HIGH threshold
VSTh
ST disable threshold hysteresis
voltage 2)
RDSON
10
V
Open drain ON resistance
1
VVS = 5.2V;
IST = 50mA
fST
Clock frequency
50
100
2. not tested in production: guaranteed by design and verified in characterization
5. tested with differed values in production but guaranteed by design and verified in characterization
7/17
L9903
Figure 4. Timing of the ISO-interface
V
TX
0.7 • V V C C
0.3 • V V C C
0.3 • V V C C
t
V
K
t KL
t KH
tKf
t Kr
80 %
I K > I K SC
0.55 • V V S
0.45 • V V S
20%
t
VR X
t RXL
t RXH
0.7 • V VC C
0.3 • V V C C
t
op e n d r ain
tr ansis tor at
K-pin
t SH
ON
O FF
Figure 5. Timing of the drivers for the external MOS regarding the inputs DIR and PWM
PWM
or
DIR
50%
tGHXLH
tGHXr
t
tGHXHL tGHXf
80%
GHX
20%
tGLXHL tGLXf
tGLXLH
tGLXr
t
80%
GLX
20%
t
8/17
L9903
Figure 6. I(V) characteristics of the K-Line for TX = HIGH and VVS=13.5V
IK [mA]
0.2
~5
0
k
Ω
0.1
0.0
-0.1
~5
0k
Ω
-0.2
-0.3
-0.4
-0.5
-20
-10
0
10
20
VK [V]
Figure 7. Driving sequence
EN
D IR
PWM
braking
G H1
G L1
G H2
Note:
Before standby mode
(EN = low) a braking phase
is mandatory to discharge
the stored energy of the
motor.
G L2
9/17
L9903
Figure 8. Charging time of an external capacitor of 10nF connected to CP pin at VVS=8V and
VVS=13.5V
voltage [V]
Charging time of a 10nF load at CP
30
CP for VS=13.5V
25
CP for VS=8V
20
15
10
EN
5
0
0
1
2
3
4
time [ms]
Figure 9. Application Circuit Diagram
VBAT
D1
VS
Voltage
Regulator
CS1
10
R CP
CS2
ST
Reference
BIAS
+
1
VCC
Charge
pump
= VSTH
f ST
VCC
VCC
DG
2
14
S1
4
5
R DIR
C1
19
M
R
GL1
R GL1
18
R
GL2
R GL2
VCC
17
R PWM
PWM
3
PR
CPR
6
Timer
RPR
ISO-Interface
RX
VCC
CB2
15
GH2
16
CB2
9
7
R RX
S2
R S2
V S2TH =
K
= 0.5 • VVS
R TX
TX
GND
10/17
R
R S1
Control Logic
µC
GH1
Thermal shutdown
REN
DIR
CB1
12
CB1
V S1TH =
EN
CP
13
Overvoltage
Undervoltage
RDG
11
8
I KH
20
GND
R
K-Line
L9903
3
FUNCTIONAL DESCRIPTION
3.1 General
The L9903 integrated circuit (IC) is designed to control four external N-channel MOS transistors in H-Bridge configuration for DC-motor driving in automotive applications. It includes an ISO9141 compatible interface. A typical
application is shown in fig.9.
3.2 Voltage supply
The IC is supplied via an external reverse battery protection diode to the VVS pin. The typical operating voltage
range is down to 8V.
The supply current consumption of the IC composes of static and a dynamic part. The static current is typically
5.8mA. The dynamical current Idyn is depending of the PWM frequency fPWM and the required gate charge QGate
of the external power mos transistor. The current can be estimated by the expression:
Idyn = 2 · fPWM · QGate
An external power transistor with a gate charge of QGate = 160nC and a PWM frequency of fPWM = 20kHz requires a dynamical supply current of Idyn = 6.4mA.
The total supply current consumption is IVS = 5.8mA + 6.4mA = 12.2mA.
3.3 Extended supply voltage range (ST)
The operating battery voltage range can be extended down to 6V using the additional components shown in
fig.7. A small inductor of L~150µH (Ipeak~500mA) in series to the battery supply builts up a step up converter
with the switching open drain output ST. The switching frequency is typical 100kHz with a fixed duty cycle of
50%. The step up converter starts below VVS < 8V, increases the supply voltage at the VS pin and switches off
at VVS > 10V to avoid EME at nominal battery voltage. The diode D2 in series with the ST pin is necessary only
for systems with negative battery voltage. No additional load can be driven by the step up converter.
Figure 10.
L9903
VBAT
L1
D1
VS
C1
C2
D2
ST
+
= VSTH
f ST
11/17
L9903
3.4 Control inputs (EN, DIR, PWM)
The cmos level inputs drive the device as shown in fig.7 and described in the truth table.
The device is activated with enable input HIGH signal. For enable input floating (not connected) or VEN=0V the
device is in standby mode. When activating the device a wake-up time of 50µs is recommended to stabilize the
internal supplies.
The DIR and PWM inputs control the driver of the external H-Bridge transistors. The motor direction can be
choosen with the DIR input, the duty cycle and frequency with the PWM input. Unconnected inputs are defined
by internal pull up resistors. During wake-up and braking and before disactivating the IC via enable both inputs
should be driven HIGH.
Table 6. Truth table:
Status
Control inputs
Driver stage for external
power MOS
Device status
Diagnostic
Comment
EN
DIR
PWM
TS
OV
UV
SC
GH1
GL1
GH2
GL2
DG
1
0
x
x
x
x
x
x
R7)
R
R7)
R
T
standby mode
2
1
x
x
1
0
0
0
L
L
L
L
L
thermal
shutdown
3
1
x
x
0
1
0
0
L
L
L
L
L
overvoltage
4
1
x
x
0
0
1
0
L
L
L
L
L
undervoltage
5
1
x
x
0
0
0
1
X6)
X6)
X6)
X6
L
short circuit 6)
6
1
0
0
0
0
0
0
L
H
H
L
H
7
1
x
1
0
0
0
0
H
L
H
L
H
8
1
1
0
0
0
0
0
H
L
L
H
H
Symbols: x Don't care
braking mode
R:Resistive output
TS:Thermal shutdown
0: Logic LOW or not active
L: Output in sink condition
OV:Overvoltage
1: Logic HIGH or active
H: Output in source condition
UV:Undervoltage
T: Tristate
SC:Short Circuit
6. Only those external MOS transistors of the H-Bridge which are in short circuit condition are switched off. All others remain driven
by DIR and PWM.
7. See Application Note AN2229
3.5 Thermal shutdown
When the junction temperature exceeds TJSD all driver are switched in sink condition (L), the K- output is off and
the diagnostic DG is LOW until the junction temperature drops below TJSD - TJHYST.
3.6 Overvoltage Shutdown
When the supply voltage VVS exceeds the overvoltage threshold VVSOVH all driver are switched in sink condition
(L), the K- output is off and the diagnostic DG is LOW.
3.7 Undervoltage Shutdown
For supply voltages below the undervoltage disable threshold the gate driver remains in sink condition (L) and
the diagnostic DG is low.
12/17
L9903
3.8 Short Circuit Detection
The output voltage at the S1 and S2 pin of the H-Bridge is monitored by comparators to detect shorts to ground
or battery. The activated external highside MOS transistor will be switched off if the voltage drop remains below
the comparator threshold voltage VS1TH and VS2TH for longer than the short current detection time tSCd. The
transistor remains in off condition, the diagnostic output goes LOW until the DIR or PWM input status will be
changed. The status doesn't change for the other MOS transistors. The external lowside MOS transistor will be
switched off if the voltage drop passes over the comparator threshold voltage VS1TH and VS2TH for longer than
the short current detection time tSCd. The transistor remains in off condition, the diagnostic output goes LOW
until the DIR or PWM input status will be changed. The status doesn't change for the other MOS transistors.
3.9 Diagnostic Output (DG)
The diagnostic output provides a real time error detection, if monitors the following error stacks: Thermal shutdown, overvoltage shutdown , undervoltage shutdown and short circuit shutdown. The open drain output with
internal pull up resistor is LOW if an error is occuring.
3.10 Bootstrap capacitor (CB1,CB2)
To ensure, that the external power MOS transistors reach the required RDSON, a minimum gate source voltage
of 5V for logic level and 10V for standard power MOS transistors has to be guaranteed. The highside transistors
require a gate voltage higher than the supply voltage. This is achieved with the internal chargepump circuit in
combination with the bootstrap capacitor. The bootstrap capacitor is charged, when the highside MOS transistor
is OFF and the lowside is ON. When the lowside is switched OFF, the charged bootstrap capacitor is able to
supply the gate driver of the highside power MOS transistor. For effective charging the values of the bootstrap
capacitors should be larger than the gate-source capacitance of the power MOS and respect the required PWM
ratio.
3.11 Chargepump circuit (CP)
The reverse battery protection can be obtained with an external N-channel MOS transistor as shown in fig.6. In
this case its drain-bulk diode provides the protection. The output CP is intended to drive the gate of this transistor above the battery voltage to switch on the MOS and to bypass the drain-bulk diode with the RDSON. The
CP has a connection to VS through an internal diode and a 20kΩ resistor.
3.12 Gate drivers for the external N-channel power MOS transistors (GH1, GH2, GL1, GL2)
High level at EN activates the driver of the external MOS under control of the DIR and PWM inputs (see truth
table and driving sequence fig.4). The external power MOS gates are connected via series resistors to the device to reduce electro magnetic emission (EME) of the system. The resistors influence the switching behaviour.
They have to be choosen carefully. Too large resistors enlarge the charging and discharging time of the power
MOS gate and can generate cross current in the halfbridges. The driver assures a longer switching delay time
from source to sink stage in order to prevent the cross conduction.
The gate source voltage is limited to 14V. The charge/discharge current is limited by the RDSON of the driver.
The drivers are not protected against shorts.
3.13 Programmable cross conduction protection
The external power MOS transistors in H-Bridge ( two half bridges) configuration are switched on with an additional delay time tCCP to prevent cross conduction in the halfbridge. The cross conduction protection time tCCP
is determined by the external capacitor CPR and resistor RPR at the PR pin. The capacitor CPR is charged up
to the voltage limit VPRH. A level change on the control inputs DIR and PWM switches off the concerned external
MOS transistor and the charging source at the PR pin. The resistor RPR discharges the capacitor CPR. The concerned external power MOS transistor will be switched on again when the voltage at PR reaches the value of
VPRL. After that the CPR will be charged again. The capacitor CPR should be choosen between 100pF and 1nF.
The resistor RPR should be higher than 7kW. The delay time can be expressed as follows:
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L9903
tCCP= RPR · CPR · ln NPR
with NPR= VPRH / VPRL = 2
tCCP= 0.69 · RPR · CPR
3.14 ISO-Interface
The ISO-Interface provides the communication between the micro controller and a serial bus with a baud rate
up to 60kbit/s via a single wire which is VBAT and GND compatible. The logic level transmission input TX drives
the open drain K-output. The K output can be connected to a serial bus with a pull up resistor to VBAT. The Kpin is protected against overvoltage, short to GND and VS and can be driven beyond VVS and GND. During lack
of VVS or GND the output shows high impedance characteristic. The open drain output RX with an internal pull
up resistor monitors the status at the K-pin to read the received data and control the transmitted data. Short
circuit condition at K-pin is recognized if the internal open drain transistor isn't able to pull the voltage potential
at K-pin below the threshold of 0.45·VVS. Then the RX stays in high condition. A timer starts and switches the
open drain transistor after typ. 20µs off. A next low at the TX input resets the timer and the open drain transistor
switches on again.
Figure 11. Functional schematic of the ISO-interface
RX
K
R RX
=
VCC
0.5 •V VS
R TX
TX
I KH
R
Q
S
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R delay
T SH
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Figure 12. SO20 Mechanical Data & Package Dimensions
mm
inch
DIM.
MIN.
TYP.
MAX.
MIN.
TYP.
MAX.
A
2.35
2.65
0.093
0.104
A1
0.10
0.30
0.004
0.012
B
0.33
0.51
0.013
0.200
C
0.23
0.32
0.009
0.013
D (1)
12.60
13.00
0.496
0.512
E
7.40
7.60
0.291
0.299
e
1.27
0.050
H
10.0
10.65
0.394
0.419
h
0.25
0.75
0.010
0.030
L
0.40
1.27
0.016
0.050
k
ddd
OUTLINE AND
MECHANICAL DATA
0˚ (min.), 8˚ (max.)
0.10
0.004
(1) “D” dimension does not include mold flash, protusions or gate
burrs. Mold flash, protusions or gate burrs shall not exceed
0.15mm per side.
SO20
0016022 D
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Table 7. Revision History
Date
Revision
January 2004
3
Migration from ST-Press to EDOCS DMS
October 2005
4
Inserted on pag 12 AN2229 ref.
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Description of Changes
L9903
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