ROHS AMS4106 Technical data

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Advanced AMS4106

Monolithic 5A SYNCHRONUS PWM BUCK CONVERTER Systems

RoHS compliant

FEATURES APPLICATIONS

• Internal MOSFET driver with Integrated High Side • LCD TVs and LCD monitors

• Uses External Low Side MOSFET • Computer Peripherals

• Adjustable output voltage dawn to 0.600V • Portable (Notebook) Computers

• External Clock Synchronization • Industrial power supply

• Built in Start/Stop UVLO • Point of regulation for high performance electronics

• Over Current and Thermal Protection • Consumer Electronics

• Shutdown supply current < 1uA • Audio Power Amplifiers

• Frequency range 100KHz to 750KHz

GENERAL DESCRIPTION

The AMS4106 is a medium output current synchronous buck converter. The high side device is integrated into the device. The AMS4106 provides an adaptive gate drive for the extern al FET. For low current operation this can be replaced with a Schottk y diode allowing asynchronous operation. The part has either a fixed internal present PWM frequency of 250 kHz, or externally adjustable up to 600 kHz, allowing smaller inductors where efficiency is less critical and faster transient response is needed. The part uses current mode control for simple compensation and ease of use with low ESR capacitors. It uses a programmable soft start to reduce inrush current and allow large output capacitors to be used where very low ripple is required. The part has enable pin with virtual zero power in shutdown mode. A power good is provided with open collector to facilitate power ready functions. The part is available in SOIC 16 thermally enhanced packages.

ORDERING INFORMATION

OUTPUT PACKAGE TYPE TEMP.

VOLTAGE 16 Lead SOIC RANGE

Adjustable AMS4106S -25ºC to 125ºC

TYPICAL APPLICATION PIN CONNECTIONS

Advanced Monolithic Systems, Inc.

16 Lead SOIC

(S)

1

PWRGD

2

SS

3

GND

4

VPWR VPWR

5

V

IN

6

COMP

7

F/B

8

16 15

1314LX 12

11

10

9

FDR PGND

LX

BST

ENABLE

F SET

Top View

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PIN DESCRIPTION

AMS4106

PIN NUMBERS

1 PWRGD Power good output. Open collector output. A low on the pin indicates that the output is less

2 SS Soft start pin connect a capacitor to GND, to slow the start up. 3 GND Analog ground-internally connected to the sensitive analog ground circuitry.

4, 5 VPWR Input supply voltage, 4.5 V to 20 V. Must bypass with a low ESR 10–µF ceramic capacitor.

6 VIN Input supply voltage, 4.5 V to 20 V powers up the internal circuitry. Must bypass with a

7 COMP Error amplifier outpu t. Connect frequency compensation network from COMP to GND. 8 F/B Input pin of the error comparator.

9 F SET External frequency set 100 Khz-750Khz. 10 ENABLE Logic enable/disable device function. 11 BST Boost voltage for the output stage drive. Connect a capacitor between LX pin and Boost.

12, 13, 14 LX Phase node- Connect to external FET and external L-C filter.

15 PGND Power Ground-No isy internal ground-Return currents from the FDR driver output return

NAME DESCRIPTION

than the desired output voltage. There is an internal rising filter on the output of the PWRGD comparator.

low ESR 10–

through the PGND

µF ceramic capacitor.

16 FDR Gate drive for low side MOSFET. Connect gate of n-channel MOSFET.

Advanced Monolithic Systems, Inc.

http://www.BDTIC.com/AMS

AMS4106

ABSOLUTE MAXIMUM RATINGS

VIN -0.3V to 30V LX Internally Limited F/B -0.3 to 8.0V FDR (steady state current) 500 mA EN -0.3V to 8.0V COMP 3 mA FSET -0.3V to 4.0V FDR (steady state current) 100 mA SS -0.3V to 4.0V LX (steady state current) 500 mA BST VI (PH) + 8.0V COMP 3 mA FDR -0.3V to 8.5V SS PWRGD 10 mA PWRGD 0.3V to 30V AGND to PGND ±0.3V COMP 0.3V to 30V ESD 2kV LX -1.5V to 30V Junction Temperature +150°C Lead Temperature1,6 mm for 10 sec. 260°C Storage Temperature -65°C to +150°C

Stresses beyond those listed under absolute maximum ratings may cause permanent d a mage to the device. These are stress ratings only, and functional operation of the device at these or any other conditions beyond those in dicated under recommended operating conditions is not implied. Exposure to absolute-maximum-rated conditions for extended periods may affect device reliability.

ELECTRICAL CHARACTERISTICS

Electrical Characteristics at TJ = 25 °C and Vin=12V (unless otherwise noted)

PARAMETER

SUPPLY CURRENT

Quiescent current

I

Q

VIN

Start threshold voltage Stop threshold voltage

Hysteresis

TEST CONDITIONS

Operating Current, LX pin open, No external low side MOSFET,

Shutdown, EN= 0V

Min. Typ. Max.

3.69 3.97 V

AMS4106

3 12 mA

0.5

4.32 4.49 V

350 mV

Units

µA

REFERENCE SYSTEM ACCURACY

Reference voltage

OSCILLATOR (RT PIN)

Internally set PWM switching frequency

ERROR AMPLIFIER F/B and COMP PINS

Error amplifier Sink current Running Error amplifier Source current Running Error amplifier Source current Start-up

Advanced Monolithic Systems, Inc.

TJ = 25 oC 0.588 T

= 125 oC

J

F set open F set to GND F set to VCC

0.600 0.612 V

0.600 V

200 250 300

kHz

60 85

1.0 98

20

kHz

µA

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AMS4106

ELECTRICAL CHARACTERISTICS (continued)

Electrical Characteristics at TJ = -40 °C to 125 °C and Vin = 4.5V (unless otherwise noted)

PARAMETER

Soft Start (SS) 2.22

POWER GOOD (PWRGD PIN)

Power good threshold Rising voltage

PWR GD

Output saturation voltage Output saturation voltage Open collector leakage Voltage on PWRGD = 6 V

CURRENT LIMIT

Current limit VIN = 12 6.1 6.5 7.5 A Current limit Hiccup Time f = 500 kHz 4.5 ms

THERMAL SHUTDOWN

Thermal shutdown trip point 145 Thermal shutdown hysteresis

LOW SIDE EXTERNAL FET DRIVE

Turn on rise time, (10%/90%)

Deadtime

(1)

OUTPUT POWER MOSFETS (LX PIN)

Lx node voltage when disabled DC conditions and no load, EN = 0 V 0.5 V

diode

r

High side power switch

DS (ON)

(1) Specified by design, not production tested.

Advanced Monolithic Systems, Inc.

f

= 250 kHz 4.6 Internal soft start (10% to 90%)

= 500 kHz

f

TEST CONDITIONS

Min. Typ. Max.

f = 250 kHz

= 500 kHz

f

= 1 mA, VIN > 4.5 V

I

sink

= 1 µA, VIN = 0 V

I

sink

VIN = 4.5V, Capacitive load = 1000 pF 15

10

AMS4106

2.3

95% 4 Rising edge delay 2

0.05 V

0.075 V 2

VIN = 8 V, Capacitive load = 1000 pF 12 VIN = 12 V 60 ns

VIN = 4.5 V sink/ source 7.5 Driver ON resistance VIN = 12 V sink/ source 5

VIN = 4.5 V, Idc = 100 mA 1.13 1.42 Voltage drop, low side FET and VIN = 12 V, Idc = 100 mA 1.08 1.38

VIN = 4.5 V, BST-LX = 4.5 V, Io = 0.5 A VIN = 12 V, BST-LX = 8 V, I

o =

0.5 A

60 40 m

Units

µA ms

ms

µA

°C °C

ns

Ω

V

Ω

ROHS AMS4106 Technical data

Specifications and Main Features

Frequently Asked Questions

User Manual