Fairchild FAN8060 service manual

February 2009

FAN8060

1.2MHz, 1A Synchronous Step-Down DC/DC Regulator

FAN8060 — 1.2MHz, 1A Synchronous Step-Down DC/DC Regulator

Features

 Current Mode Control  Over 96% Efficient  Selectable Continuous Output Current: 500mA/1A  2.5V to 5.5V Input Voltage Range  Output Voltage as Low as 1.2V  1.2MHz Operating Frequency  Less than 1µA Shutdown Current  External Synchronization from 500kHz to 2MHz  100% Duty Cycle  Synchronous Switching FET; no Schottky Diode

Required

 Stable with Ceramic Capacitors  Light Load Mode with Pulse Skipping  External Compensation  External Soft-Start  Overload / Short-Circuit Protection  Under-Voltage Lockout  Thermal Shutdown  10-Lead 3x3mm Green MLP Package

Applications

 PDAs  GPS Devices  MP3 Players  Mini PCI  Digital Cameras  Peripheral Ports  DSP Core  USB Devices  PCMCIA  Cable Modem  Data Cards

Application Diagram

Description

The FAN8060 is a highly efficient, monolithic, currentmode, step-down synchronous regulator. It can provide 1A continuous current from 2.5V to 5.5V input voltage. The output voltage can be adjusted from 1.2V up to the input voltage with an external voltage divider.

External compensation and soft-start allow for design optimization and flexibility. High-frequency operation allows for all-ceramic solutions and small footprints. In addition, a user-selectable current limit provides protection against output overload and short circuit.

FAN8060 features pulse skipping to achieve higher efficiency during light load operation. 100% duty cycle capability enables power solutions to extend the drop out voltage.

Provision for external synchronization allows users to minimize input capacitors and manage EMI in solutions.

FAN8060 is available in a green, low profile, 10-Lead 3x3mm MLP package.

Figure 1. Typical Application Circuit

Ordering Information

FAN8060 — 1.2MHz, 1A Synchronous Step-Down DC/DC Regulator

Part Number

FAN8060EMPX -40 to +85°C Green

For Fairchild’s definition of “green” Eco Status, please vis i t : http://www.fairchildsemi.com/company/green/rohs_green.html.

Operating

Temperature Range

Eco Status

10-Pin, 3x3mm Molded Leadless Package (MLP)

Package Packing Method

Tape & Reel

Pin Configuration

Figure 2. Pin Configuration (Top View)

Note:

1. Connect exposed PAD to AGND

Pin Definitions

Pin Name Function

1 EN

2 AVIN

3 PVIN

4 SW

5 PGND

6 SYNC

7 SS

8 COMP

9 FB

10 AGND

Enable. Enables operation when pulled to logic HIGH. Analog Input Voltage. All internal control circuits are connected to this supply. Power Input Voltage. Power stage supply voltage. Switching Node. The drains of both PMOS and NMOS. Power Ground. Power return and source of the power NMOS Synchronization. Use this pin to synchronize the part to an external clock. This pin also

controls current limit threshold. Tie to ground for 1.0A or tie to V current. When an external clock is applied, the default current setting is 1A. This pin has a pull-down resistor of 450KΩ.

Soft-Start. A capacitor connected between this pin and AGND can set soft-start time. Compensation. Error amplifier output. Connect the external compensation network between

this pin and AGND.

Output Voltage Feedback. Connect through a resistor divider to set the output voltage. Analog Ground. Ground return for all internal control circuits.

for 0.5A continuous load

IN

Absolute Maximum Ratings

Stresses exceeding the absolute maximum ratings may damage the device. The device may not function or be operable above the recommended operating conditions and stressing the parts to these levels is not recommended. In addition, extended exposure to stresses above the recommended operating conditions may affect device reliability. The absolute maximum ratings are stress ratings only. All voltage values, except differential voltages, are given with respect to the network ground terminal. Stress beyond those listed under Absolute Maximum Ratings may cause permanent damage to the device.

Symbols Parameter Min. Max. Unit

V

PVIN (AGND=PGND) -0.3 6.0 V

PVIN

V

AVIN (AGND=PGND) -0.3 6.0 V

AVIN

VSW Switch Voltage, SW to GND -0.3 VIN + 0.3 or 6.0 V

All other pins except COMP -0.3 6.0 V

T

Storage Temperature -65 +150 °C

STG

TJ Junction Temperature -40 +125 °C

ESD Electrostatic Discharge Protection

Note:

2. COMP pin has an internal clamp to 1.5V.

Human Body Model, JESD22-A114

Charged Device Model, JESD22-C101

2.0 kV

2.5

FAN8060 — 1.2MHz, 1A Synchronous Step-Down DC/DC Regulator

Recommended Operating Conditions

The Recommended Operating Conditions table defines the conditions for actual device operation. Recommended operating conditions are specified to ensure optimal performance to the datasheet specifications. Fairchild does not recommend exceeding them or designing to Absolute Maximum Ratings.

Symbol Parameter Min. Max. Unit

VIN Supply Voltage 2.5 5.5 V

TA Ambient Operating Temperature -40 +85 °C

Thermal Information

Symbol Parameter Min. Typ. Max. Units

T

Storage Temperature -65 +150 °C

STG

TL Lead Soldering Temperature, 30 Seconds +300 °C

θJA θJc

PD Total Power Dissipation in the package, TA=25°C

Note:

3. Typical thermal resistance when mounted on a four-layer PCB. Actual results are dependent upon mounting method and surface related to the design.

Thermal Resistance: Junction-to-Ambient 49 °C/W

Thermal Resistance: Junction-to-Case

(3)

8 °C/W

(3)

1.3 W

FAN8060 — 1.2MHz, 1A Synchronous Step-Down DC/DC Regulator

Electrical Characteristics

VIN=5.0V, V

Symbol Parameter Conditions Min. Typ. Max. Units

Basic Operation

VIN VIN Operating Voltage AVIN=PVIN 2.5 5.5 V

IQ Quiescent Current VEN=5 V, VSS=0V 250 371 500 µA

ISD Shutdown Current VEN=0V 0.34 0.60 µA

V

UVLO

V

UVLOHYS

V

ENH

V

ENL

R

ONPMOS

R

ONNMOS

I

LIM

f

Oscillator Frequency TA=25°C 1.105 1.21 1.35 MHz

OSC

V

SYNC

f

SYNC

t

SYNC

I

Error Amplifier

AMP

GCS Current Sense Gain

V

REF

IFB FB Bias Current TA=25°C -0.10 -0.06 0 µA

ISS Soft-Start Current -4.8 -4.5 -4.3 µA

=2.5 V, C

OUT

=10µF, CIN=10µF, over operating range, unless otherwise noted.

OUT

VIN Under-Voltage Lockout Rising VIN 2.10 2.19 2.25 V

VIN Under-Voltage Lockout Hysteresis 70 mV

Enable High Input Voltage 1.70 2.00 V

Enable Low Input Voltage 0.80 1.22 V

PMOS On Resistance

NMOS On Resistance

(4)

VIN=5V 200

V

=3.3V 300

IN

VIN=5V 200

mΩ

VIN=3.3V 300

V

=0V 1.2

P-Channel Current Limit

=0.7V, VIN=5V, 100% Duty Cycle

V

FB

SYNC

V

SYNC=VIN

0.6

A

SYNC Threshold Rising Edge VIN/2 V

Synchronization Frequency V

Minimum SYNC Pulse Width V

=Square Wave 500 2000 KHz

SYNC

On Time 100 ns

SYNC

Sink/Source Current 30 45 60 µA

(4)

G

700 1000 1400 µA/V

EA

(4)

A

550 V/V

VEA

(4)

3 A/V

Reference Voltage for Temperature

Co-efficient, see Figure 12

Measured at FB Pin

=25°C

T

A

1.181 1.205 1.229 V

Protections

T

Over-Temperature Threshold

OTP

T

Over-Temperature Hysteresis +20 °C

HYS

(4)

+165 °C

Note:

4. Guaranteed by design and characterization; not production tested.

Fairchild FAN8060 service manual

Specifications and Main Features

Frequently Asked Questions

User Manual