STMICROELECTRONICS L9823

L9823
Octal Low-Side Driver for bulb, resistive and inductive loads with
serial input control, output protection and diagnostic
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OUTPUTS CURRENT CAPABILITY UP TO
0.5A
CASCADABLE SPI CONTROL FOR
OUTPUTS
RESET FUNCTION WITH RESET SIGNAL OR
UNDERVOLTAGE AT VDD
PROGRAMMABLE INTRINSIC OUTPUT
VOLTAGE CLAMPING AT TYP. 50V FOR
INDUCTIVE SWITCHING
OVERCURRENT SHUTDOWN WITH LATCHOFF FOR EVERY WRITE CYCLE (SFPD = LOW)
INDEPENDENT THERMAL SHUTDOWN OF
OUTPUTS (SOA PROTECTION)
OUTPUT STATUS DATA AVAILABLE ON THE
SPI USING 8-BIT I/O PROTOCOL UP TO 3.0MHZ
LOW STANDBY CURRENT WITH RESET =
LOW (TYP 35µA @ VDD)
OPEN LOAD DETECTION (OUTPUTS OFF)
SINGLE VDD LOGIC SUPPLY
HIGH EMS IMMUNITY AND LOW EME
(CONTROLLED OUTPUT SLOPES)
FULL FUNCTIONALITY OF THE REMAINING
DEVICE AT NEGATIVE VOLTAGE DROP ON
SO24 (20+2+2)
ORDERING NUMBER: L9823
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OUTPUTS (-1,5V OR -3,0A)
OUTPUT MODE PROGRAMMABLE FOR
SUSTAINED CURRENT LIMIT OR
SHUTDOWN
DESCRIPTION
L9823 is a Octal Low-Side Driver Circuit, dedicated
for automotive applications. Output voltage clamping
is provided for flyback current recirculation, when inductive loads are driven. Chip Select and cascadable
Serial 8-bit Interface for outputs control and diagnostic data transfer.
BLOCK DIAGRAM
16
VDD
SFPD
15
OUT0
-
OL0
24
VDG
+
IOL
SCLK
3
SI
4
Output Latch
10
Shift Register
CSB
SPI
Interface
=
SO
Q0
Q1
Q2
Q3
Q4
Q5
Q6
Q7
Q0
Gate
Control
+
ISCB 0
OT0
Diag0
Diag0
Q1
Diag1
Diag1
Diag2
Q2
Diag3
Diag2
Diag4
Diag5
Q3
Diag6 Diag3
Diag7
Q4
Diag4
-
Over
Temperature
Detect
+
=
CH0
CH1
CH2
CH3
CH4
9
Q5
Diag5
CH5
Reset
Q6
Diag6
CH7
Q7
Diag7
CH7
22
Reset
Undervoltage
RESET
Reset
OUT1
23
OUT2
14
OUT3
13
OUT4
12
OUT5
11
OUT6
2
OUT7
1
GND 5 -8
17 - 20
April 2003
1/12
L9823
PIN FUNCTION
N°
Pin
1
Out 7
Output 7
2
Out 6
Output 6
3
SCLK
SCLK. The system clock pin (SCLK) clocks the internal shift registers of the L9823. The serial
input pin (SI) accepts data into the input shift register on the falling edge of the SCLK signal while
the serial output pin (SO) shifts data information out of the shift register on the rising edge of the
SCLK signal. False clocking of the shift register must be avoided to guarantee validity of data. It
is essential that the SCLK pin be in a logic low state whenever chip select bar pin (CSB) makes
any transition. For this reason, it is recommended though not necessary, that the SCLK pin be
kept in a low logic state as long as the device is not accessed (CSB in logic high state). When
CSB is in a logic high state, any signal at the SCLK and SI pin is ignored and SO is tri-stated
(high-impedance).
4
SI
SI. This pin is for the input of serial instruction data. SI information is read in on the falling edge
of SCLK. A logic high state present on this pin when the SCLK signal rises will program a
specific output OFF, and in turn, turns OFF the specific output on the rising edge of the CSB
signal. Conversely, a logic low state present on the SI pin will program the output ON, and in
turn, turns ON the specific output on the rising edge of the CSB signal. To program the eight
outputs of the L9823 ON or OFF, an eight bit serial stream of data is required to be entered into
the SI pin starting with Output 7, followed by Output 6, Output 5, etc., to Output 0. For each rise
of the SCLK signal, with CSB held in a logic low state, a databit instruction (ON or OFF) is
loaded into the shift register per the databit SI state. The shift register is full after eight bits of
information have been entered. To preserve data integrity, care should be taken to not transition
SI as SCLK transitions from a low-to-high logic state.
5
GND
GND
6
GND
GND
7
GND
GND
8
GND
GND
9
SO
SO. The serial output (SO) pin is the tri-stateable output from the shift register. The SO pin
remains in a high impedance state until the CSB pin goes to a logic low state. The SO data
reports the drain status, either high or low. The SO pin changes state on the rising edge of SCLK
and reads out on the falling edge of SCLK. When an output is OFF and not faulted, the
corresponding SO databit is a high state. When SO an output is ON, and there is no fault, the
corresponding databit on the SO pin will be a low logic state. The SI / SO shifting of data follows
a first-in-first-out protocol with both input and output words transferring the Most Significant Bit
(MSB) first. The SO pin is not affected by the status of the Reset pin.
10
CSB
CSB. The system MCU selects the L9823 to be communicated with through the use of the CSB
pin. Whenever the pin is in a logic low state, data can be transferred from the MCU to the L9823
and vise versa. Clocked-in data from the MCU is transferred from the L9823 shift register and
latched into the power outputs on the rising edge of the CSB signal. On the falling edge of the
CSB signal, drain status information is transferred from the power outputs and loaded into the
device's shift register. The CSB pin also controls the output driver of the serial output pin.
Whenever the CSB pin goes to a logic low state, the SO pin output driver is enabled allowing
information to be transferred from the L9823 to the MCU. To avoid any spurious data, it is
essential that the high-to-low transition of the CSB signal occur only when SCLK is in a logic low
state.
11
Out 5
Output 5
12
Out 4
Output 4
13
Out 3
Output 3
2/12
Description
L9823
PIN FUNCTION (continued)
N°
Pin
Description
14
Out 2
Output 2
15
SFPD
SFPD. The Short Fault Protect Disable (SFPD) pin is used to disable the overcurrent latch-OFF.
This feature allows control of incandescent loads where in-rush currents exceed the device's
analog current limits. Essentially the SFPD pin determines whether the L9823 output(s) will
instantly shutdown upon sensing an output short or remain ON in a current limiting mode of
operation until the output short is removed or thermal shutdown is reached. If the SFPD pin is
tied to VDD the L9823 output(s) will remain ON in a current limited mode of operation upon
encountering a load short to supply. If the SFPD pin is grounded, a short circuit will immediately
shutdown only the output affected. Other outputs not having a fault condition will operate
normally.
16
VDD
VDD
17
GND
GND
18
GND
GND
19
GND
GND
20
GND
GND
21
NC
22
Reset
Reset. The Reset pin is active low and used to clear the SPI shift register and in doing so sets all
output switches OFF. With the device in a system with an MCU; upon initial system power up,
the MCU holds the Reset pin of the device in a logic low state ensuring all outputs to be OFF
until the VDD pin voltages are adequate for predictable operation. After the L9823 is Reset, the
MCU is ready to assert system control with all output switches initially OFF. The Reset pin is
active low and has an internal pull-down incorporated to ensure operational predictability
should the external pull-down of the MCU open circuit. The internal pull-up is to afford safe and
easy interfacing to the MCU. The Reset pin of the L9823 should be pulled to a logic low state for
a duration of at least 160ns to ensure reliable Reset.
23
Out 1
Output 1
24
Out 0
Output 0
Not Connected
ABSOLUTE MAXIMUM RATINGS
For voltages and currents applied externally to the device. Exceeding limits may cause damage to the device.
Symbol
VDD
Parameter
Supply voltage
Value
Unit
-0.3 to 7
V
Inputs and data lines
(CSB, SCLK, SI, Reset, SFPD, SO)
VIN
VSDO
IIN
Voltage
(CSB, SCLK, SI, Reset, SFPD)
Voltage (SO)
Protection diodes current 1) T ≤ 1ms
-0.3 to 7
-0.3 to VDD+0.3
V
-20 to 20 1)
mA
-1.5 to 45
V
Outputs (Out0 ... Out7)
VOUT Cont
Continuous output voltage
3/12
L9823
ABSOLUTE MAXIMUM RATINGS (continued)
Symbol
Parameter
Value
Unit
-3 to IOUT LIM
A
-10 2) to 2
A
VOUT Cont
Continuous output current
IOUT PEAK
Output current
EOUTclamp
Output clamp energy 3)
50
mJ
IOUT LIM
Output current (self limit)
2
A
Note
1) All inputs are protected against ESD according to MIL 883C; tested with HBM C = 100pF, R = 1500Ω at ±2KV. It corresponds to
a dissipated energy E ≤ 0.2mJ (data available upon request).
2) Transient pulses in accordance to DIN40839 part 1, 3 and ISO 7637 Part 1, 3.
3) Max. output clamp energy at Tj = 150°C, using single non-repetitive pulse of 500mA
THERMAL DATA
Symbol
Parameter
Value
Unit
155 (Min.), 180 (Typ.)
°C
Thermal shutdown
TLIM
Thermal shutdown threshold
Thermal resistance (junction-to-Lead)
RthjL-one
Single output (junction lead)
25 (Max.)
°C/W
RthjL-all
All outputs (junction lead)
20 (Max.)
°C/W
Storage Temperature
-55 to 150
°C
Tstg
ELECTRICAL CHARACTERISTCS (4.5V ≤ VDD ≤ 5.5V; -40°C ≤ TJ ≤ 150°C; unless otherwise specified
Symbol
Parameter
Test Condition
Min.
Typ.
Max.
Unit
35
70
µA
<1
10
µA
6
mA
10
mA
2.5
3.95
V
Supply voltage
IDDSTB
IDDleak
Standby current
leakage current
Reset = LOW and / or
VDDRES>VDD > 0.5V
VDD < 0.5V
IDDOPM
Operating mode
IOUT0 ... 7 = 500mA
SPI - SCLK = 3MHz
CSB = LOW
SO no load
∆IDD rev
∆IDD during reverse output
current
Iout rev = -2.5A
VDD RES
Undervoltage Reset
Reset of all registers and disable
of all outputs
Inputs (CSB, SCLK, SI, Reset, SFPD)
VINL
Low level
-0.3
0.2·VDD
V
VINH
High level
0.7·VDD
VDD+0.3
V
Vhyst
Hysteresis voltage
0.5·VDD
V
4/12
0.5
1.2
L9823
ELECTRICAL CHARACTERISTCS (continued)
Symbol
Parameter
IIN
Input current
RIN
Pullup resistance
(CSB, SI)
Pulldown resistance
(SFPD, Reset, SCLK)
CIN
Input capacitance
Test Condition
VIN = VDD
Min.
Typ.
Max.
Unit
-10
10
µA
50
250
kΩ
10
pF
Serial data outputs
VSOH
High output level
ISO = -4mA
VSOL
Low output level
ISO = 3,2mA
ISOL
Tristate leakage current
CSB = high; 0V ≤ VSO ≤ VDD
CSO
Output capacitance
fSO = 300kHz, 0V ≤ VSO ≤ VDD
VDD -0.4
V
-10
0.4
V
10
µA
20
pF
10
µA
60
V
1.5
1.25
Ω
Ω
300
pF
Outputs OUT 0 ... 7
IOUTL0 - 7 Leakage current
OUTx = OFF; VOUTx = 16V;
VDD ≤ VDD RES and / or Reset = Low
Tj ≤ 85°C
-10
Output clamp voltage
2mA ≤ IOUT clamp ≤ IOUT LIM
IOUT test = 20mA with correlation
45
RDSon
On resistance OUT 0 ... 7
IOUT = 500mA;Tj = +150°C
Tj = +25°C
COUT
Output capacitance
VOUT = 16V; f = 1MHz
VOUT
clamp
<1µA
1
0.8
Outputs short circuit protection
ISCB
Overcurrent shutoff threshold
IOUT LIM
Short circuit current limitation
tdly SCB
Short circuit shutdown delay
SFPD = Low, VOUT ≥ VDG
SFPD = Low, VOUT ≥ VDG
CSB = 50% to
IOUT ≤ 1/2 IOUT LIM
0.5
1.6
2.5
A
0.5
1.6
2.5
A
70
150
250
µs
0.5·VDD
0.55·V
0.6·VDD
V
Diagnostics
VDG
Diagnostic threshold voltage
DD
IOUT OL
Open load detection sink current
Vout = VDG
Output programmed OFF
30
60
100
µA
tdly SFPD
Diagnostic detection filter time
SFPD = Low, VOUT ≥ VDG
CSB = 50% to
valid data at SO
70
150
250
µs
20
µs
Outputs timing
tdon
Turn ON delay
CSB = 50% to RL = 50Ω
VOUT = 0,9Vbat, Vbat = 16V
5/12
L9823
ELECTRICAL CHARACTERISTCS (continued)
Symbol
tdoff
Parameter
Test Condition
Min.
Typ.
Max.
Unit
20
µs
Turn OFF delay
CSB = 50% to RL = 50Ω
VOUT = 0,1·Vbat, Vbat = 16V
dVon/dt
Turn ON voltage slew-rate
90% to 30% of Vbat;
RL = 50Ω; Vbat = 16V
0.7
2.1
3.5
V/µs
dVoff/dt
Turn OFF voltage slew-rate
30% to 90% of Vbat;
RL = 50Ω; Vbat = 16V
0.7
2.1
3.5
V/µs
dVoff
clamp/dt
Turn OFF voltage clamp slew-rate 30% to 80% of VOUT clamp
RL = 500Ω
0.7
2.1
5.5
V/µs
Serial diagnostic link (Load capacitor at SO = 200pF)
fsclk
Clock frequency
tclh
tcll
50% duty cycle
3
MHz
Minimum time SCLK = HIGH
160
ns
Minimum time SCLK = LOW
160
ns
4.9V ≤ VDD ≤ 5.1V
tpcld
Propagation delay
SCLK to data at SO valid
tcsdv
CSB = LOW to data at SO active
tsclch
SCLK low before CSB low
Setup time SCLK to CSB change
H/L
100
ns
thclcl
SCLK change L/H after CSB =
Low
Setup time CSB to SCLK change
L/H
100
ns
tscld
SI input setup time
SCLK change H/L after SI data
valid
20
ns
thcld
SI input hold time
SI data hold after SCLK change
H/L
tsclcl
SCLK low before CSB high
150
ns
thclch
SCLK high after CSB high
15,
ns
tpchdz
CSB L/H to output data float
100
ns
tReset
Minimum Reset time Reset = Low
160
ns
Outputs Control Tables :
Outputs:
6/12
SI-bit
0
1
Output
on
off
100
ns
100
ns
20
ns
L9823
Output Control register structure :
MSB
Q7
LSB
Q6
Q5
Q4
Q3
Q2
Q1
Q0
Control-bit output 7
Control-bit output 6
Control-bit output 5
Control-bit output 4
Control-bit output 3
Control-bit output 2
Control-bit output 1
Control-bit output 0
Power outputs characteristics
for flyback current, outputs short circuit protection and diagnostics
For output currents flowing into the circuit the output voltages are limited. The typical value of this voltage is 50V.
This function allows that the flyback current of a inductive load recirculates into the circuit; the flyback energy is
absorbed in the chip.
Output short circuit protection SFPD = Low (dedicated for loads without inrush current): when the output current
exceeds the short circuit threshold, the corresponding output overload latch is set after a delay time tdly SCB and
the output is switched off. The delay timer is started after each rise of CSB and valid datas are transfered to the
output control register. If the short takes place after the delay time has elapsed the shutdown is immediate (within 15µs).
Output short circuit protection SFPD = High (dedicated for loads with inrush current, as lamps): when the load
current would exceed the short circuit limit value, the corresponding output goes in a current regulation mode.
The output current is determined by the output characteristics and the output voltage depends on the load resistance. In this mode high power is dissipated in the output transistor and its temperature increases rapidly.
When the power transistor temperature exceeds the thermal shutdown threshold, the overload latch is set and
the corresponding output switched off.
For the load diagnostic in output off condition each output features a diagnostic current sink, of typ 60µA.
FUNCTIONAL DESCRIPTION
General
The L9823 integrated circuit features 8 power low-side-driver outputs. Data is transmitted to the device using
the Serial Peripheral Interface = SPI protocol. The power outputs features voltage clamping function for flyback
current recirculation and are protected against short circuit to Vbat.
The diagnostics recognizes two outputs fault conditions: 1) overcurrent and thermal overload in switch-ON condition and 2) open load or short to GND in switch-OFF condition for all outputs. The outputs status can be read
out via the serial interface.
The chip internal Reset is a OR function of the external Reset signal and internally generated undervoltage Reset signal.
7/12
L9823
Output Stages Control
Each output is controlled with its latch and with a common Reset line, which enables all outputs.
The control data are transmitted via the SI input, the timing of the serial interface is shown in Fig. 1.
The device is selected with low CSB signal and the input data are transferred into the 8 bit shift register at every
falling SCLK edge. The rising edge of the CSB latches the new data from the shift register to the drivers.
Figure 1. Timing of the Serial Interface
CSB
tsclch
thclcl
tclh
tcll
tsclcl
thclch
SCLK
tcsdv
SO
tpcld
not defined
tpchdz
D7
D0
thcld
tscld
SI
D7
D6
D0
The SPI register data are transferred to the output latch at rising CSB edge. The digital filter between CSB and
the output latch ensures that the data are transferred only after 8 SCLK cycles or multiple of 8 SCLK cycles
since the last CSB falling edge. The CSB changes only at low SCLK.
Diagnostics
The output voltage at all outputs is compared with the diagnostic threshold, typ 0,55 • VDD = VDG.
Diagnostic Table for outputs:
Output
Output-voltage
Status-bit
Output-mode
off
> DG-threshold
high
correct operation
off
< DG-threshold
low
fault condition 2)
on
< DG-threshold
low
correct operation
on
> DG-threshold
high
fault condition 1)
Fault condition 1) "output short circuit to Vbat" : For SFPD = Low the output was switched on and the voltage at
the output exceeded the diagnostics threshold due to overcurrent, the output overload latch was set and the
output has been switched off. The diagnostic bit is high.
: For SFPD = High the output was switched on and the voltage at the output exceeds the diagnostics threshold.
The output operates in current regulation mode or has been switched off due to thermal shutdown. The status
bit is high.
Fault condition 2) "open load" or "output short circuit to GND" : the output is switched off and the voltage at the
output drops below the diagnostics threshold, because the load current is lower than the output diagnostic current source, the load is interrupted. The diagnostic bit is low.
At the falling edge of CSB the output status data are transferred to the shift register. When SCB is low, data bits
contained in the shift register are transferred to SO output at every rising SCLK edge.
8/12
L9823
Figure 2. Pulse Diagram to Read the Outputs Status Register
CSB
SCLK
SI
SO
MSB
6
MSB
5
6
4
5
3
4
2
3
1
2
LSB
1
LSB
Figure 3. Structure of the Outputs Status Register
MSB
LSB
Diag7Diag6Diag5Diag4Diag3Diag2Diag1Diag0
Diagnostic-bit ou
Diagnostic-bit ou
Diagnostic-bit ou
Diagnostic-bit ou
Diagnostic-bit ou
Diagnostic-bit ou
Diagnostic-bit ou
Diagnostic-bit ou
9/12
L9823
APPLICATIONS INFORMATION
The typical application diagram for parallel Input SPI control is shown in Figure 4.
Figure 4. Typical Application Circuit Diagram for the L9823 Circuit.
VDD
16
VOLTAGE
REGULATOR
VDD
SFPD
OUT0
-
OL0
15
24
VDG
+
IOL
3
SI
4
Output Latch
SCLK
Shift Register
10
SPI
Interface
=
CSB
SO
Q0
Q1
Q2
Q3
Q4
Q5
Q6
Q7
Reset
Reset
Reset
SCLK
SI
Undervoltage
RESET
SO
µP
CSB2 ... 7
22
Q0
Reset
Gate
Control
+
ISCB 0
OT0
Diag0
Diag0
Q1
Diag1
Diag1
Diag2
Q2
Diag3
Diag2
Diag4
Diag5
Q3
Diag6 Diag3
Diag7
Q4
Diag4
9
VBAT
-
Over
Temperature
Detect
+
=
CH0
CH1
CH2
CH3
CH4
Q5
Diag5
CH5
Q6
Diag6
CH7
Q7
Diag7
CH7
U459
OUT1
23
OUT2
14
OUT3
13
OUT4
12
OUT5
11
OUT6
2
OUT7
1
R, L loads
GND 5 -8
17 - 20
U459
For higher current driving capability more outputs of the same kind can be paralleled. In this case the maximum
flyback energy should not exceed the limit value for single output.
The immunity of the circuit with respect to the transients at the output is verified during the characterization for
Test Pulses 1, 2 and 3a, 3b, DIN40839 or ISO7637 part 3. The Test Pulses are coupled to the outputs with
200pF series capacitor. The correct function of the circuit with the Test Pulses coupled to the outputs is verified
during the characterization for the typical application with R = 16Ω to 200Ω, L= 0 to 600mH loads. All outputs
withstand testpulses without damage.
10/12
L9823
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)
15.20
15.60
0.598
0.614
E
7.40
7.60
0.291
0.299
e
1.27
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
ddd
Weight: 0.60gr
0.050
H
k
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.
SO24
0070769 C
11/12
L9823
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by implication or otherwise under any patent or patent rights of STMicroelectronics. Specifications mentioned in this publication are subject
to change without notice. This publication supersedes and replaces all information previously supplied. STMicroelectronics products are not
authorized for use as critical components in life support devices or systems without express written approval of STMicroelectronics.
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