Allegro MicroSystems A8600 Manual

Quadruple Output Regulator with Two High-Side Switches,
Features and Benefits
• Four independent, high current switching regulators
• Adjustable 1.0 A/±1.5% always-on asynchronous buck
regulator with an integrated 150 mΩ MOSFET (SW1)
▫ Employs PFM to deliver 3.3 V/40 µA while drawing less
than 50 µA from V of 12 V
IN
▫ Operates down to at least 3.6 V
• Adjustable 1.5 A/±1.5% asynchronous buck regulator with
an integrated 120 mΩ high-side MOSFET (SW2)
• Adjustable 2.0 A/±1.5% asynchronous buck regulator with
an integrated 110 mΩ MOSFET (SW3)
• Adjustable ±1.5% synchronous buck controller with
integrated gate drivers and current sensing (SW4)
• Fixed 425 kHz, interleaved PWM switching frequency
• EN/SYNC input for PWM frequency scaling
• Adjustable soft-start time for each switching regulator
• All switching regulators provide prebias startup with zero
reverse current
• All switching regulators have overvoltage protection
• External compensation for all switching regulators
Continued on the next page...
Package: 48-pin LQFP (suffix JP)
Not to scale
A8600-DS, Rev. 4
BU/ACC Voltage Detectors, and Mute Delay
IN
Switcher 1 Switcher 2
(SW1) (SW2)
Adjustable Adjustable
Output Voltage Output Voltage
1.0 A / 2.5 A 1.5 A / 2.5 A
AVG PEAK AVG
Always-On
PWM / PFM PWM
Asynchronous Asynchronous
Buck Buck
Regulator Regulator
Charge
Pump
Enable and
Synchronization
(EN/SYNC)
425 kHz
180° Shift
Figure 1. A8600 major features
Description
Designed to provide the power supply requirements of next
generation car audio and infotainment systems, the A8600
provides all the control and protection circuitry to produce
four high current regulators, each with ±1.5% accuracy. The
A8600 includes control circuitry to implement three adjustable,
asynchronous buck regulators with integrated MOSFETs. Also,
the A8600 provides the control circuitry, gate drivers, and
current sensing to implement a synchronous buck controller
with external MOSFETs. In standby mode, the A8600 draws
less than 50 µA from V
frequency modulation (PFM) to deliver 3.3 V/40 µA via the
always-on regulator, SW1. The always-on regulator operates
down to at least V
Features of the A8600 include: an EN/SYNC input to either
turn the A8600 on/off or increase/decrease the base pulse
width modulation (PWM) frequency, four adjustable soft-start
times, and four external compensation pins. Output voltage
monitoring of switchers SW2, SW3, and SW4 is provided
by a single, open-drain POK output. In addition, the A8600
provides two high voltage, high-side switches with foldback
overcurrent protection. These two high-side switches actively
block reverse current. The A8600 also provides direct battery
(BU) and switched (accessory) battery (ACC) detectors and
a mute pulse output with an adjustable delay.
Continued on the next page...
Switcher 3
(SW3)
Adjustable
Output Voltage Output Voltage
2.0 A / 2.5 A
PEAK AVG PEAK
PWM
Asynchronous
Buck
Regulator
High-Side Switch 1
BU and ACC
(S1)
Detectors
1.0 Ω Total
with
Foldback Limiting
High-Side Switch 2
(S2)
Mute Pulse
1.0 Ω Total
with Delay
with
Foldback Limiting
of 12 V while employing pulse
IN
of 3.6 V (V falling).
IN IN
Switcher 4
(SW4)
Adjustable
Adjustable I
LIM
PWM
Synchronous
Buck
Controller
A8600