HIP0082 Intersil Corporation, HIP0082 Datasheet - Page 6

• Manufacturer Part Number: HIP0082
• Description: Quad Power Drivers with Serial Diagnostic Interface
• Manufacturer: Intersil Corporation

Functional Description
Power Output Stages
The Block Diagram details the equivalent logic control of
each power output driver. Each power output stage has a
separately controlled input with hysteresis and is active low
with a pull-up to maintain an off state when there is no input.
Each output driver has sensors for short circuit, open load
and short-to-ground fault detection. The drive to each output
is also controlled by the POR, Reset and an RS latch that
switches off the output when a short circuit occurs. An inter-
nal zener diode feedback from the drain to gate of the output
driver provides over voltage clamp protection.
For the HIP0082, each power output channel has a low
r
allel. The high r
detection while providing one-tenth of the output load current.
The HIP0084 output is modified into one low r
and provides controlled slew rate switching. In addition, the
HIP0084 requires an external zener and resistor network for
OL detection. Refer to the Block Diagram, Specifications and
OL Detection information.
Reset Operation
An active low reset on the RST pin or the writing of a Low to
the Test Bit is required to guarantee normal operation after
power-up. When RST is in the low state all outputs are off
and all registers and counters are reset. When the reset pin
is taken high the IC remains in reset mode for a time t
When the RST pin is switched active low, the on-chip reset
circuitry ensures that the output stages are turned off, all
counters and registers are reset, and the programmable
functions are in their default states. The default state for the
Test Bit is a Low. The default state for the short-circuit cur-
rent for outputs 3 and 4 is the higher value for 5A maximum
current operation (ISC Bit Low). The default state for the
open-load delay times for each output is the higher value
between 3ms and 5.2ms (Td_OLx Bits Low).
Low Power Drive Shutdown
As part of the POR function, there is a low voltage power
drive shutdown when the supply voltage, V
the voltage threshold, V
condition the output stages are held off.
Over Voltage Clamp Operation
A drain-to-gate zener diode on each output driver internally
clamps an over voltage pulse, including the kick pulse gener-
ated when turning off an inductive load. While providing over
voltage protection, it is not part of the diagnostic feedback
via the Diagnostic Register.
Short-Circuit (SC) Protection
If the output current is above the current limit for a time delay
greater than t
sponding bit in the diagnostic register set. The current level for
shutdown on outputs 3 and 4 is programmable between 2A
DS(ON)
(Q
O
) and a high r
SC
DS(ON)
the output is switched off and the corre-
driver is used to enhance the open load
DS(ON)
CC(LOW)
(Q
OL
. During the low voltage
) NDMOS drivers in par-
CC
DS(ON)
drops below
HIP0082, HIP0084
RST
driver
.
6
and 5A with the ISC bit. After shutdown, the output remains
off until the corresponding input is taken high and again low.
Open-Load (OL) Detection
Load currents are monitored while the outputs are ON. If the
open load current falls below the fault threshold current,
I
The open load fault bits (OLx) are stored in the diagnostic
register as shown in Figure 1. The output of open-load
detector circuit is input to the Diagnostic Register via the delay
filter and is also connected directly to the R/W Shift Register
for potential monitoring via the serial interface.
For the HIP0082 in an ON state, if a load current falls below
the I
detected and the low r
transistor (Q
(Q
increased from a low level, Q
teresis, to a normal mode of operation as defined by the
I
I
The HIP0084 OL detection diagnostics differ from the
HIP0082. The HIP0084 does not have an internal pullup
resistor (shown in the Block Diagram of the HIP0082 as
R
OUTx and V
OL and a SG fault condition is required, an external
pulldown resistor from OUTx-to-Ground may be used. For a
distinction between an OL and SG fault condition, an exter-
nal pullup resistor in series with a diode between OUTx and
V
greater than (V
external power supply voltage for the outputs, V
diode drop of the series diode; V
comparator threshold level for OUTx and I
load current detection threshold of OUTx. While the values
for pullup and pulldown resistors are not critical, they
should not be minimally small. In either case, they should
be typically 10k
Output Short-to-Ground (SG) Detection
When the voltage on an output pin is below V
output is off, a ground short is detected and stored in the
diagnostic register after a delay t
short-to-ground (SG) comparators are also connected
directly to the diagnostic register so that they can be moni-
tored via the serial interface. Where V
range of 2.4V to 2.9V, I
15mA to 100mA for the HIP0084 and 3mA to 20mA for the
HIP0082.
Serial Interface Operation
Microprocessor communication to the diagnostic/control reg-
isters is via a 4 wire serial interface. Data control is bidirec-
tional, the direction of data transfer being dependent on the
state of the R/W pin (See Figure 2).
OLF
OL(HYS)
OL(MAX)
OL
CC
OL
, the open load fault bit is set after a delay time t
OL
) continues to conduct. If the load current is then
in series with the diode, D
is needed. The pullup resistor must have a value
threshold level, a low load current condition is
, both Q
limits. When the output current is higher than
O
CC
) is switched off. The high r
CC
. Where no failure distinction between an
O
or greater.
and Q
- V
DS(ON)
BE
OL
OLF
- V
O
conduct.
SG
is specified in the range of
, high current DMOS output
will be switched on, with hys-
)/I
SG
OL
SG
OLF
) connected between
is the short-to-ground
. The outputs of the
SG
where V
is specified in the
OLF
DS(ON)
is the open-
SG
CC
BE
and the
is the
is the
driver
DOL
.