A4410 Datasheet, PDF (1/41 Pages) Allegro MicroSystems – Programmable watchdog timer with a 30 ms activation delay

A4410
Adjustable Frequency Buck or Buck/Boost Pre-Regulator with a
Synchronous Buck, 3 Internal LDOs, Window Watchdog Timer, and NPOR
FEATURES AND BENEFITS
• Automotive AEC-Q100 qualified
• 2.8 V_IN to 36 V_IN operating range, 40 V_IN maximum
• Buck or buck/boost pre-regulator (VREG)
• Adjustable PWM switching frequency: 250 kHz –
2.4 MHz
• PWM frequency can be synchronized to external clock
• 1.25 V/750 mA_DC/1 A_PEAK synchronous buck (1V25)
• 3.3 V (3V3) and 5 V (V5) internal LDO regulators with
fold back short circuit protections
• 5 V (V5P) internal tracking LDO regulator with fold
back short circuit and short-to-battery protections
• TRACK sets either 3V3 or V5 as the reference for V5P
• Power-on reset with fixed delay of 15 ms for 1V25/3V3
UV and OV protection (NPOR)
• Programmable watchdog timer with a 30 ms activation
delay
• Active low, watchdog timer enable/disable pin (WD_ENn)
• Dual band gaps for increased reliability: BG_VREF,
BG_FAULT
Continued on next page...
APPLICATIONS
• Automotive Control Modules for:
□□Electronic Power
□□Emissions Control
Steering (EPS)
Modules
□□Transmission Control
□□Other automotive
(TCU)
applications
□□Advanced Braking
Systems (ABS)
PACKAGE: 38-Pin eTSSOP (suffix LV)
Not to scale
DESCRIPTION
The A4410 is power management IC that uses a buck or buck/
boost pre-regulator to efficiently convert automotive battery
voltages into a tightly regulated intermediate voltage complete
with control, diagnostics, and protections. The output of the
pre-regulator supplies a 5 V/250 mA_MAX tracking/protected
LDO, a 3.3 V/160 mA_MAX LDO, a 5 V/150 mA_MAX LDO,
and a 1.25 V/750 mA_DC/1 A_PEAK synchronous buck regulator.
Designed to supply CAN or microprocessor power supplies in
high temperature environments the A4410 is ideal for under
hood applications.
Enable inputs to the A4410 include a logic level (ENB) and two
high-voltage (ENBAT1 and ENBAT2). The A4410 provides
flexibility by including a TRACK pin to set the reference of
the tracking regulator to either the 5 V or the 3.3 V output,
so the A4410 can be adapted across multiple platforms with
different sensors and supply rails.
Diagnostic outputs from the A4410 include a power-on-reset
output (NPOR) with a fixed 15 ms delay, an ENBAT1 and
ENBAT2 status outputs, and a PowerOK output for the 5 V
and 5 V protected LDOs (POK5V). Dual bandgaps, one for
regulation and one for fault checking, improve long-term
reliability of the A4410.
The A4410 contains a Window Watchdog timer that can be
programmed to accept a wide range of clock frequencies
(WD_ADJ). The watchdog timer has a fixed 30 ms activation
delay to accommodate processor startup. The watchdog timer
has an enable/disable pin (active LOW, WD_ENn) to facilitate
initial factory programming or field re-flash programming.
Protection features include under and over voltage lockout on
all four CPU supply rails. In case of a shorted output, all linear
regulators feature fold back over current protection. In addition,
the V5P output is protected from a short-to-battery event. Both
Continued on next page...
5.35 V
(VREG)
Buck-Boost
Pre-regulator
3.3 V LDO
(3V3)
with Foldback
Protection
1.25 V
(1V25)
Sync. Buck
Regulator
Dual
Bandgaps
Charge
Pump
Thermal
Shutdown
(TSD)
POK5V
Output
Programmable
Pulse Width
Watchdog
Timer with
Activation Delay
5 V LDO
(V5)
with Foldback
Protection
3V3
NPOR
Output
V5
Tracking
Control
2:1 MUX
5 V LDO
(V5P)
with Tracking,
Foldback, and
Short to VBAT
Protetction
REF
A4410-DS
A4410 Simplified Block Diagram