A8585KLKTR-T

A8585KLKTR-T Datasheet

A8585

Part	Datasheet
A8585KLKTR-T	A8585KLKTR-T (pdf)

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A8585 Wide Input Voltage, 2 A Buck Regulator Family with Low IQ Mode • Automotive AEC-Q100 qualified • Withstands surge input to 40 VIN for load dump • Operates down to VIN typ , VIN max for idle stop • Utilizes pulse frequency modulation PFM for low IQ mode • Function options: Selectable PWM / Low IQ PFM mode, or Selectable 10 uA Sleep mode automatic PWM / Low IQ PFM mode selection • Fixed output voltage options V or 5 V with accuracy • Delivers up to A of output current • Integrated 110 mΩ high-side MOSFET • Adjustable switching frequency from 300 to 550 kHz to 605 kHz with sync • EMI Reduction Features: Frequency dithering Controlled switching node • External synchronization capability The A8585 family is designed to provide the power supply requirements of next generation car audio and infotainment systems. The A8585 family provides all the control and protection circuitry to produce a high current regulator with output voltage accuracy. In PWM mode, the A8585 family employs current mode control to provide simple compensation, excellent stability, and fast transient response. In Low IQ mode, the A8585 family employs pulse frequency modulation PFM to draw less than 33 µA from 12 VIN while supplying V/40 µA. When operational, the A8585 family operates down to at least VIN falling . The selectable Sleep mode feature allows for very low standby current. Features of the A8585 family include a programmable PWM switching frequency. The regulator switching frequency can be synchronized to an external clock. The A8585 has external compensation to optimize stability and transient response for a wide range of external components and applications. The A8585 has a fixed soft start time of 5 ms. Continued on the next Continued on the next Package 10-pin SOIC with exposed thermal pad suffix LK Not to scale Applications: • Automotive Instrument Clusters Audio Systems Navigation HVAC • Home audio • Network and telecom • Industrial [A8585-2, -3 only] Typical Application Diagram 1 VIN 2 VIN A8585-x BOOT VOUT CBOOT 47 nF D1 2 A/40 V VOUT CO SYNC RFSET 3 PWM/PFM [A8585, -1] EN/SLEEP [A8585-2, -3] 4 FSET /SYNCPWM 7 COMP RPU 6 NPOR NPOR CP RZ See table 2 for recommended component values A8585-DS A8585 Wide Input Voltage, 2 A Buck Regulator Family with Low IQ Mode Specifications Typical Application Diagram Ordering Selection Guide Absolute Maximum Ratings Thermal Characteristics Functional Block Diagram Pin-out Diagrams and Terminal List Electrical Characteristics Characteristic Performance Protection Features Undervoltage Lockout UVLO Pulse-by-Pulse Overcurrent Protection OCP Overcurrent Protection OCP and Hiccup Mode 20 BOOT Capacitor Protection Asynchronous Diode Protection Overvoltage Protection OVP Pin-to-Ground and Pin-to-Pin Short Protections 21 Thermal Shutdown TSD Functional Description Overview Reference Voltage PWM Switching Frequency EN/SLEEP Input for A8585-2 and A8585-3 PWM/PFM Input for A8585 and A8585-1 PWM Synchronization Transconductance Error Amplifier Slope Compensation Current Sense Amplifier Power MOSFETs BOOT Regulator Pulse Width Modulation PWM Mode Low-IQ Pulse Frequency Modulation PFM Mode 17 Soft Start Startup and Inrush Current Control Pre-Biased Startup Active Low Power-On Reset NPOR Output Design and Component Selection PWM Switching Frequency RFSET Output Inductor Output Capacitors Low-IQ PFM Output Voltage Ripple Calculation Input Capacitors Asynchronous Diode D1 Bootstrap Capacitor Compensation Components RZ, and CP A Generalized Tuning Procedure Power Dissipation and Thermal Calculations PCB Component Placement and Routing Package Drawing Allegro MicroSystems, LLC

PDF Datasheet Preview

A8585

Wide Input Voltage, 2 A Buck Regulator Family with Low IQ Mode
• Automotive AEC-Q100 qualified
• Withstands surge input to 40 VIN for load dump
• Operates down to VIN typ , VIN max for idle
stop
• Utilizes pulse frequency modulation PFM for low IQ
mode
• Function options:

Selectable PWM / Low IQ PFM mode, or Selectable 10 uA Sleep mode automatic PWM / Low IQ

PFM mode selection
• Fixed output voltage options V or 5 V with
accuracy
• Delivers up to A of output current
• Integrated 110 mΩ high-side MOSFET
• Adjustable switching frequency from 300 to 550 kHz to
605 kHz with sync
• EMI Reduction Features:

Frequency dithering Controlled switching node
• External synchronization capability

The A8585 family is designed to provide the power supply requirements of next generation car audio and infotainment systems. The A8585 family provides all the control and protection circuitry to produce a high current regulator with output voltage accuracy.

In PWM mode, the A8585 family employs current mode control to provide simple compensation, excellent stability, and fast transient response. In Low IQ mode, the A8585 family employs pulse frequency modulation PFM to draw less than 33 µA from 12 VIN while supplying V/40 µA. When operational, the A8585 family operates down to at least VIN falling . The selectable Sleep mode feature allows for very low standby current.

Features of the A8585 family include a programmable PWM switching frequency. The regulator switching frequency can be synchronized to an external clock. The A8585 has external compensation to optimize stability and transient response for a wide range of external components and applications. The A8585 has a fixed soft start time of 5 ms.

Continued on the next

Continued on the next

Package 10-pin SOIC with exposed thermal pad suffix LK

Not to scale

Applications:
• Automotive Instrument Clusters Audio Systems Navigation HVAC
• Home audio
• Network and telecom
• Industrial
[A8585-2, -3 only]

Typical Application Diagram
1 VIN
2 VIN

A8585-x

BOOT

VOUT

CBOOT 47 nF

D1 2 A/40 V

VOUT CO

SYNC RFSET
3 PWM/PFM [A8585, -1] EN/SLEEP [A8585-2, -3]
4 FSET /SYNCPWM
7 COMP

RPU 6 NPOR

NPOR

CP RZ

See table 2 for recommended component values

A8585-DS

A8585

Wide Input Voltage, 2 A Buck Regulator Family with Low IQ Mode
Specifications Typical Application Diagram Ordering Selection Guide Absolute Maximum Ratings Thermal Characteristics Functional Block Diagram Pin-out Diagrams and Terminal List Electrical Characteristics Characteristic Performance

Protection Features

Undervoltage Lockout UVLO

Pulse-by-Pulse Overcurrent Protection OCP

Overcurrent Protection OCP and Hiccup Mode 20

BOOT Capacitor Protection

Asynchronous Diode Protection

Overvoltage Protection OVP

Pin-to-Ground and Pin-to-Pin Short Protections 21

Thermal Shutdown TSD

Functional Description

Overview

Reference Voltage

PWM Switching Frequency

EN/SLEEP Input for A8585-2 and A8585-3

PWM/PFM Input for A8585 and A8585-1

PWM Synchronization

Transconductance Error Amplifier

Slope Compensation

Current Sense Amplifier

Power MOSFETs

BOOT Regulator

Pulse Width Modulation PWM Mode

Low-IQ Pulse Frequency Modulation PFM Mode 17

Soft Start Startup and Inrush Current Control

Pre-Biased Startup

Active Low Power-On Reset NPOR Output

Design and Component Selection

PWM Switching Frequency RFSET

Output Inductor

Output Capacitors

Low-IQ PFM Output Voltage Ripple Calculation

Input Capacitors

Asynchronous Diode D1

Bootstrap Capacitor

Compensation Components RZ, and CP

A Generalized Tuning Procedure

Power Dissipation and Thermal Calculations

PCB Component Placement and Routing

Package Drawing

Allegro MicroSystems, LLC

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Datasheet ID: A8585KLKTR-T 516086