STMICROELECTRONICS L98SI

L98SI
OCTAL SERIAL SOLENOID DRIVER
.
..
..
.
.
..
EIGHT LOW RDSon DMOS OUTPUTS
(0.5Ω AT I O = 1A @ 25°C VCC = 5V± 5%)
8 BIT SERIAL INPUT DATA (SPI)
8 BIT SERIAL DIAGNOSTIC OUTPUT FOR
OVERLOADAND OPENCIRCUIT CONDITIONS
OUTPUT SHORT CIRCUIT PROTECTION
CHIP ENABLESELECTFUNCTION (active low)
INTERNAL 36V CLAMPING FOR EACH OUTPUT
CASCADABLE WITH ANOTHER OCTAL
DRIVER
LOW QUIESCENT CURRENT (10mA MAX.)
PACKAGE PowerSO20
DESCRIPTION
The L98SI is an octal low side solenoiddriver rea
lized in Multipower-BCD technologyparticularlysuited for driving lamps, relays and solenoids in indu-
MULTIPOWER BCD TECHNOLOGY
PowerSO20
ORDERING NUMBER: L98SI
strial environment. The L98SI DMOS outputshave
very low power consumption.
Data is transmitted serially to the device using the
Serial Peripheral Interface (SPI) protocol.
The L98SI features the outputs status monitoring
function.
BLOCK DIAGRAM
April 1998
1/9
L98SI
PIN CONNECTION (top view)
GND
1
20
GND
SO
2
19
SI
VDD
3
18
SCLK
RESET
4
17
CE
OUT7
5
16
OUT0
OUT6
6
15
OUT1
OUT5
7
14
OUT2
OUT4
8
13
OUT3
N.C.
9
12
N.C.
GND
10
11
GND
D94AT119
ABSOLUTE MAXIMUM RATINGS
Symbol
Parameter
Value
Unit
VDD
DC Logic Supply
– 0.7
VO
Output Voltage
internally clamped
II
IOdc
Tj, Tstg
EX
Input Transient Current
(CE, SI, SCLK, RESET, SO) :
Duration Time t = 1s,
VI < 0
VI > VCC
7
– 25
+ 25
Continuous Output Current (for each output)
Int. Limited
Junction and Storage Temperature Range
– 40
150
Max Clamping Energy (for each output)
200
V
V
mA
mA
A
°C
mJ
THERMAL DATA
Symbol
2/9
Value
Unit
R th j-case
Thermal Resistance Junction-Case
Parameter
Max.
1.5
°C/W
R th j-amb
Thermal Resistance Junction-Ambient
Max.
60
°C/W
L98SI
PIN DESCRIPTION
VCC
Logic supply voltage - nominally 5V
GROUND
Device Ground.This groundapplies for the logic circuits as well as the power output stages.
RESET
Asynchronousreset for the outputstages,the parallel latch and the shift register inside the L98SI. This
pin is active low and it must not be left floating. A power on clear function may be implemented connecting this pin to VCC with an external resistor and to
ground with an external capacitor.
CE
Chip Enable. Data is transferred from the shift registers to the outputs on the rising edge of this signal.
The falling edge of this signal sets the shift register
with the output voltage sense bits coming from the
output stages. The output driver for the SO pin is
enabled when this pin is low.
SO
Serial Output. This pin is the serial output from the
shift register and it is tri-stated when CE is high. A
high for a data bit on this pin indicates that the par-
ticular output is high. A low on this pin for a data bit
indicates that the output is low.
Comparing the serial output bits with the previous
serial input bits the external microcontroller implements the diagnostic data supplied by the L98SI.
SI
Serial Input. This pin is the serial data input. A high
on thispin will programa particularoutputto be OFF,
while a low will turn it ON.
SCLK
Serial Clock. This pin clocks the shift register. New
SO data will appear on every rising edge of this pin
and new SI data will be latched on every SCLK’s falling edge into the shift register.
OUTPUTS 00-07
Power output pins. The input and outputbits correspondingto 07 are sent and received first via the SPI
bus and 00is the last. The outputsare provided with
current limiting and voltage sense functions for fault
indication and protection. The nominal load current
for these outputs is 500mA, but the current limiting
is set to a minimum of 1.05A.The outputsalso have
on board clamps set at about 36V for recirculation
of inductive load current.
ELECTRICAL CHARACTERISTICS (VCC = 5V ± 5%. Tj = – 40 to 125°C ; unless otherwise speciifed)
Symbol
Parameter
Test Conditions
VOC
Output Clamping Volt.
IO = 0.5A, Output Programmed OFF
IOleak
Out. Leakage Current
VO = 24V, Output Progr. OFF
R DSon
On Resistance
Output Progr. ON
IO = 0.5A
IO = 0.8A
IO = 1A
With Fault Reset Disabled
Min.
Typ.
30
0.55
0.55
0.55
Max.
Unit
40
V
1
mA
1
1
1
Ω
Ω
Ω
IOL
Out. Self Limiting
Current
Output Progr. ON
tPHL
Turn-on Delay
IO = 500mA
No Reactive Load
10
µs
tP
Turn-off Delay
IO = 500mA
No Reactive Load
10
µs
Fault Refer. Voltage
Output Progr. OFF
Fault detected if VO > VOREF
1.6
2
V
Fault Reset Delay
(after CE L to H
transition)
See fig. 3
75
250
µs
Output OFF Voltage
Output Pin Floating.cOutput Progr. OFF,
1.0
V
VOREF
tUD
VOFF
1.05
A
3/9
L98SI
ELECTRICAL CHARACTERISTICS (Continued)
Symbol
Parameter
Test Conditions
Min.
Typ.
Max.
Unit
INPUT BUFFER (SI, CE, SCLK and RESET pins)
V T–
Threshold Voltage at
Falling Edge
SCLK only
VCC = 5V ± 10%
V T+
Threshold Voltage at
Rising Edge
SCLK only
VCC = 5V ± 10%
VH
Hysteresis Voltage
VT+ – VT–
0.85
2.5
V
II
Input Current
VCC = 5.50V, 0 < VI < VCC
– 10
+ 10
µA
CI
Input Capacitance
0 < VI < VCC
20
nF
V
0.2VCC
0.6
V
0.7VCC
V
4.15
V
OUTPUT BUFFER (SO pin)
VSOL
Output LOW Voltage
IO = 1.6mA
VSOH
Output HIGH Voltage
IO = 0.8mA
ISOtl
Output Tristate Leakage
Current
0 < VO < VCC, CE Pin Held High,
VCC = 5.25V
C SO
Output Capacitance
ICC
Quiescent Supply
Current at VCC Pin
0.4
V
V
VCC
– 1.3V
20
µA
0 < VO < VCC
CE Pin Held High
20
pF
All Outputs Progr. ON. IO = 0.5A
per Output Simultaneously
10
mA
2
MHz
– 20
SERIAL PERIPHERAL INTERFACE (see fig. 2, timing diagram)
fop
Operating Frequency
D.C.
tlead
Enable Lead Time
250
ns
tlag
Enable Lag Time
250
ns
twSCKH
Clock HIGH Time
200
ns
twSCKL
Clock LOW Time
200
ns
tsu
Data Setup Time
75
ns
tH
Data Hold Time
75
ns
tEN
Enable Time
250
ns
tDIS
Disable Time
250
ns
Data Valid Time
100
ns
tV
4/9
trSO
Rise Time (SO output)
VCC = 20 to 70% CL = 200pF
50
ns
tfSO
Fall Time (SO output)
VCC = 70 to 20% CL = 200pF
50
ns
trSI
Rise Time SPI
Inputs (SCK, SI, CE)
VCC = 20 to 70% CL = 200pF
200
ns
tfSI
Fall Time SPI
Inputs (SCLK, SI, CE)
VCC = 70 to 20% CL = 200pF
200
ns
tho
Output Data Hold Time
0
µs
L98SI
FUNCTIONAL DESCRIPTION
TheL98SIDMOS outputisa lowoperatingpowerdevice featu-ring, eight 1Ω RDSON DMOS drivers with
transient protection circuits in output stages. Each
channel is independently controlled by an output
latch and a common RESET line which disables all
eightoutputs.Thedriverhaslow saturationandshort
circuitprotectionandcandriveinductiveandresistive
loads such as solenoids, lamps and relais. Data is
transmitted to the device serially using the Serial Peripheral Interface(SPI) protocol. The circuit receives
8 bitserial databy meansof the serialinput(SI)which
is stored in an internal register to control the output
drivers. The serial output (SO) provides 8 bit of diagnosticdatarepresentingthe voltagelevel at the driver output. This allows the microprocessor to
diagnose the condition of the output drivers.
The output saturation voltage is monitored by a
comparator for an out of saturation condition and is
able to unlatch the particular driver through the fault
reset line. This circuit is also cascadable with another octal driver in order to jam 8 bit multiple data.
The device is selected when the chip enable (CE)
line is low.
Additionally the (SO) is placed in a tri-state mode
when the device is deselected. The negative edge
of the (CE) transfers the voltage level of the drivers
to the shift registerand the positive edge of the (CE)
latchesthe new datafrom the shift registerto the drivers. When CE is Low, data bit contained into the
shift register is transferred to SO output at every
SCLK positive transition while data bit present at SI
input is latched into the shift register on every SCLK
negative transition.
Internal Blocks Description
The internal architecture of the device is based on
the three internal major blocks : the octal shift register for talking to the SPI bus, the octal latch for holding control bits written into the device and the octal
load driver array.
Shift Register
The shift register has both serial and parallel inputs
and serial and parallel outputs. The serial input accepts data from the SPI bus and the serial output simultaneously sends data into the SPI bus. The
parallel outputs are latched into the parallel latch inside the L98SI at the end of a datatransfer. The parallel inputsjam diagnosticdatainto the shift register
at the beginning of a data transfer cycle.
Parallel Latch
The parallel latch holds the input data from the shift
register. This data then actuates the output stages.
Individual registers in the latch may be cleared by
fault conditions in order to protect the overloaded
output stages. The entire latch may also be cleared
by the RESET signal.
Output Stages
The output stagesprovide an active low drive signal
suitable for 0.75A continuous loads. Each output
has a current limit circuit which limits the maximum
output current to at least 1.05A to allow for high inrush currents. Additionally,the outputshaveinternal
zeners set to 36 volts to clamp inductive transients
at turn-off. Each output also has a voltage comparator observing the outputnode. If the voltage exceeds 1.8V on an ON output pin, a fault condition is
assumed and the latch driving this particular stage
is reset, turning the output OFF to protect it. The timing of this action is described below. These comparators also provide diagnostic feedback data to
the shift register. Additionally, the comparatorscontainan internalpulldowncurrentwhich will causethe
cell to indicate a low output voltage if the output is
programmedOFF and the output pin is open circuited.
TIMING DATA TRANSFER
Figure #2 shows the overall timing diagram from a
byte transfer to and from the L98SI using the SPI
bus.
CE High to Low Transition
The action begins when the Chip Enable(CE) pin is
pulledlow. The tri-state Serial Output(SO)pin driver
will be enabledentire time that CE is low. At the falling edge of the CE pin, the diagnostic data from the
voltage comparatorsin the output stages will be latched into the shift register. If a particular output is
high, a logic one will be jammed into that bit in the
shift register. If the output is low, a logic zero will be
loadedthere. The most significant bit (07) shouldbe
presented at the Serial Input (SI) pin. A zero at this
pin will program an output ON, while a one will program the output OFF.
SCLK Transitions
The Serial Clock (SCLK) pin should then be pulled
high. At thispoint the diagnostic bit from the most significantoutput(07) will appearat the SO pin.A high
here indicates that the 07 pin is higher than 1.8V.
The SCLK pin shouldthen be toggledlow then high.
New SO data will appearfollowingevery rising edge
of SCLK and new SI data will be latched into the
L98SIshift registeronthe fallingedges.An unlimited
amount of data may be shifted through the device
5/9
L98SI
shift register (into the SI pin and out the SO pin), allowing theotherSPI devicesto becascadedin a daisy chain with the L98SI.
CE Low to High Transition
Once the last data bit has been shifted into the
L98SI, the CE pin should be pulled high.
At the rising edge of CE the shift register data is latched intothe parallel latch and the outputstageswill
be actuated by the new data. An internal 160µs delay timer will also be started at this rising edge (see
tUD). During the 160µs period, the outputs will be
protected only by the analog current limiting circuits
since the resetting of the parallel latches by faults
conditionswill be inhibitedduringthis period.This allows the part to overcome any high inrush currents
that may flow immediately after turn on. Once the
delay period has elapsed, the output voltages are
sensed by the comparators and any output with voltageshigher than 1.8V arelatched OFF. It shouldbe
noted that the SCLK pin should be low at both tranFigure 1 : Byte Timing with Asynchronous Reset.
6/9
sitions of the CE pin to avoid any false clocking of
theshift register. TheSCLK input is gatedby the CE
pin, so that the SCLK pin is ignored whenever the
CE pin is high.
FAULT CONDITIONS CHECK
Checking for fault conditions may be done in the following way. Clock in a new control byte. Wait 160
microseconds or so to allow the outputs to settle.
Clock in thesame controlbyte and observethe diagnostic data that comes out of the device. The diagnostic bits should be identical to the bits that were
first clockedin. Any differenceswould point to a fault
on that output.If the outputwas programmed ON by
clocking in a zero, and a one came back as the diagnosticbit forthat output,the outputpinwasstill high
and a short circuit or overload condition exists. If the
output was programmed OFF by clocking in a one,
and a zero came back as the diagnostic bit for that
output, nothing had pulled the output pin high and it
L98SI
Figure 2 : Timing Diagram.
Figure 3 : Typical Application Circuit.
7/9
L98SI
POWERSO20 PACKAGE MECHANICAL DATA
mm
DIM.
MIN.
inch
TYP.
MAX.
A
MIN.
TYP.
MAX.
3.6
a1
0.1
0.142
0.3
a2
0.004
0.012
3.3
a3
0.130
0
0.1
0.000
0.004
b
0.4
0.53
0.016
0.021
c
0.23
0.32
0.009
0.013
D (1)
15.8
16
0.622
0.630
D1
9.4
9.8
0.370
0.386
E
13.9
14.5
0.547
e
0.570
1.27
e3
0.050
11.43
E1 (1)
0.450
10.9
11.1
E2
0.429
0.437
2.9
0.114
E3
5.8
6.2
0.228
0.244
G
0
0.1
0.000
0.004
H
15.5
15.9
0.610
0.626
L
0.8
1.1
0.031
0.043
N
10° (max.)
S
8° (max)
T
10
0.394
(1) ”D and F” do not include mold flash or protrusions.
- Mold flash or protrusions shall not exceed 0.15 mm (0.006”).
- Critical dimensions: ”E”, ”G” and ”a3”
N
R
N
a2
b
DETAIL A
A
e
c
a1
DETAIL B
E
e3
D
DETAIL A
lead
20
11
slug
a3
DETAIL B
E2
E1
0.35
Gage Plane
T
- C-
S
L
SEATING PLANE
G
C
(CO PLANARITY)
1
10
PSO20MEC
h x 45°
8/9
L98SI
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.
 1998 SGS-THOMSON Microelectronics – Printed in Italy – All Rights Reserved
PowerSO-20 is a Trademark of SGS-THOMSON Microelectronics
SGS-THOMSON Microelectronics GROUP OF COMPANIES
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