A81407
Multi-Output Regulator with Buck or Buck-Boost Pre-Regulator,
4× LDO Outputs, Watchdog, 4× Gate Drivers, and SPI
DESCRIPTION
FEATURES AND BENEFITS
• A2-SIL™ pending—device features for safety-critical
systems
The A81407 is ideal for both automotive and industrial
applications, where high temperature operation, a high level
of integration, and robust solutions are required.
• Automotive AEC-Q100 qualified
• Wide input voltage range, 3.8 to 36 VIN operating range,
40 VIN maximum
• 2.2 MHz buck or buck/boost pre-regulator (VREG: 5.35 V)
with low EMI frequency dithering
• Frequency dithering and controlled slew rate help reduce
EMI/EMC
• Four internal linear regulators with foldback short-circuit
protection
The IC integrates a buck or buck/boost pre-regulator, four LDOs,
and four floating gate drivers. The pre-regulator uses a buck or
buck/boost topology to efficiently convert input voltages into a
tightly regulated intermediate voltage. Frequency dithering and
slew control help reduce EMI. The output of the pre-regulator
supplies a 3.3 V / 375 mA linear regulator, a 5 V / 150 mA linear
regulator,andtwo5V/120mAlinearregulators.Alloftheoutputs
are protected against short circuits, and two are further protected
from short-to-supply voltage in case they are used remotely.
□ VUC: selectable output (3.3 V / 5.0 V) regulator for
microcontroller
The independent floating gate drivers can be used for input
supply disconnect or reverse-supply protection. They can
also be used for switched loads such as motor phases, solid
state relays, and solenoid valves. They have the capability of
controlling N-channel MOSFETs through SPI. An integrated
charge pump allows the driver outputs to maintain the power
MOSFETs in the on-state over the full supply range with high
phase-voltage slew rates.
□ V5A: 5 V general purpose LDO regulator
□ V5P1 and V5P2: two LDO regulators with short-to-
battery protection for remote sensors
• OV and UV protection for all output rails provides ability
to monitor health of outputs
• Pulse Width Watchdog (PWWD), Window Watchdog
(WWD), and Q&A Watchdog (QAWD)
• Floating gate drivers (with charge pumps) for external
switched load control
• Analog multiplexor (AMUX) reports operational values
of multiple important parameters
• Safety signal (POE) can disable a separate function (e.g.,
motor driver) due to a Watchdog Failure
Diagnostic outputs from the A81407 include a Watchdog
Fault (WD_Fn), power-on reset (NPOR), and a fault flag
(FFn) to alert the microprocessor that a fault has occurred.
The microprocessor can read fault registers through SPI and
operational status via an analog multiplexor.
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APPLICATIONS
PACKAGE
38-Pin eTSSOP (suffix LV)
Provides system power (for microcontroller/DSP, CAN,
sensors, etc.) and high-side gate driver control (for motor
phases and other switched loads such as solenoid valves and
SS relays) in:
• Industrial applications
• Electronic power steering (EPS)
Not to scale
2
• Advanced braking systems (ABS)
• Transmission control units (TCU)
• Emissions control modules
-
(pending)
• Other automotive applications
5.35 V
(VREG)
Buck-Boost
Pre-regulator
3.3 V / 5 V
5 V LDO (V5P1)
with Foldback &
Short to VBAT
Protection
5 LDO (V5P2)
with Foldback &
Short to VBAT
Protection
5 V LDO (V5A)
with Foldback
Protection
LDO (VUC)
with Foldback
Protection
4ch
Floating
Gate
NPOR,
Pulse-Width,
Window, and
Q&A
Drivers
Thermal
Shutdown
(TSD)
Analog MUX
Output for
Status Monitor
Serial
Interface
(SPI)
WD_Fn,
POE,
FFn
Charge
Pump
Dual
Bandgap
Watchdogs
A81407 Simplified Block Diagram
A81407-DS, Rev. 2
MCO-0000748
December 1, 2020