Fairchild FAN5362 service manual

September 2011

FAN5362 3MHz, 500mA / 750mA Synchronous Buck Regulator

Features

 3MHz Fixed-Frequency Operation  45µA Typical Quiescent Current  1.80 to 3.6V Fixed Output Voltage  500mA or 750mA Output Current Capability  2.7V to 5.5V Input Voltage Range  Smooth Transitions to/from 100% Duty Cycle

when V

Drops

IN

 PFM Mode for High Efficiency in Light Load  Best-in-Class Load Transient Response  Best-in-Class Efficiency  Forced PWM and External Clock Synchronization  Internal Soft-Start  Input Under-Voltage Lockout (UVLO)  Thermal Shutdown and Overload Protection  6-Bump WLCSP, 0.4mm Pitch or 6-Lead 2 x 2mm

Ultrathin Molded Leadless Package

Applications

 SD Flash Memory Power Supply  RF Transceiver Power  Cell Phones, Smart Phones  Tablets, Netbooks  3G, LTE, WiMAX™, WiBro

®

, Ultra-Mobile PCs

®

, and WiFi® Data Cards

 Gaming Devices, Digital Cameras DC/DC Micro Modules

Description

The FAN5362 is a 500mA or 750mA, step-down, switching voltage regulator that delivers a fixed output voltage from an input voltage supply of 2.7V to 5.5V. Using a proprietary architecture with synchronous rectification, the FAN5362 is capable of delivering a peak efficiency of 96%, while maintaining efficiency over 90% with load currents as low as 1mA.

This regulator transitions seamlessly into and out of 100% duty cycle operation when the supply dips to or below the regulation setpoint and smoothly recovers full regulation without overshoot when the supply recovers.

The regulator operates at a nominal fixed frequency of 3MHz, which reduces the value of the external components to 1µH for the output inductor and 4.7µF for the output capacitor. The PWM modulator can be synchronized to an external frequency source.

At moderate and light loads, pulse frequency modulation is used to operate the device in power-save mode with a typical quiescent current of 45µA. Even with such a low quiescent current, the part exhibits excellent transient response during large load swings. At higher loads, the system automatically switches to fixed-frequency control, operating at 3MHz. In shutdown mode, the supply current drops below 1µA, reducing power consumption. For applications that require minimum ripple or fixed frequency, PFM mode can be disabled using the MODE pin.

The FAN5362 is available in 6-bump, 0.4mm pitch, WaferLevel Chip-Scale Package (WLCSP) Ultrathin Molded Leadless Package (UMLP).

MODE

A1

and 6-Lead 2 x 2mm

VIN

A2

FAN5362 — 3MHz, 500mA / 750mA Synchronous Buck Regulator

L1

SW

FB

B1

C1

1µH

C

F

Trademarks are the property of their respective owners.

OUT

Figure 1. Typical Application

B2

C2

EN

GND

C

IN

2.2 F

Ordering Information

FAN5362 — 3MHz, 500mA / 750mA Synchronous Buck Regulator

Part Number

FAN5362UC21X

FAN5362UC25X

FAN5362UC27X 2.7 500

FAN5362UC29X 2.9 500

FAN5362UC33X 3.3 500

FAN5362UMP29X 2.9 500

FAN5362UMP33X 3.3 500

Note:

1. Other voltage options available on request. Contact a Fairchild representative.

2. Preliminary; not full production release at this time. Contact a Fairchild representative for information.

Output

Voltage

(2)

2.1 750

(2)

2.5 500

Output Current (mA)

(1)

Operating

Temperature Range

-40 to 85°C

Package

WLCSP-6,

0.4mm Pitch

6-Lead, 2 x 2mm

UMLP

Packing

Method

Tape and

Reel

Table 1. Recommended Components for Circuit in Figure 1

Component Description Example Part Typical

L1

CIN

C

OUT

1H, 2012, 190m, 800mA

2.2F, 6.3V, X5R, 0402

2.2F, 6.3V, X5R, 0603

4.7F, X5R, 0603 10F, X5R, 0603

Murata LQM21PN1R0MC0

Murata GRM155R60J225ME15

GRM188R60J225KE19D

Murata GRM188R60J475M

Murata GRM188R60J106ME47D

1H

2.2F

4.7F

10.0F

Pin Configuration

Figure 2. WLCSP, Bumps Facing Down Figure 3. WLCSP, Bumps Facing Up

Pin Definitions

WLCSP

Bump #

A1 3 MODE

B1 2 SW

C1 1 FB

C2 6 GND

B2 5 EN

A2 4 VIN

UMLP

Pin #

Name Description

Logic 1 on this pin forces the IC to stay in PWM mode. Logic 0 allows the IC to automatically switch to PFM during light loads. The regulator also synchronizes its switching frequency to two times the frequency provided on this pin. Do not leave this pin floating.

Switching Node. Connect to output inductor. Feedback / V Ground. Power and IC ground. All signals are referenced to this pin. Enable. The device is in shutdown mode when voltage to this pin is <0.4V and enabled

when >1.2V. Do not leave this pin floating. Input Voltage. Connect to input power source.

. Connect to output voltage.

OUT

Figure 4. UMLP, Leads Facing Down

FAN5362 — 3MHz, 500mA / 750mA Synchronous Buck Regulator

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.

Symbol Parameter Min. Max. Unit

VIN Input Voltage –0.3 6.5 V

VSW Voltage on SW Pin –0.3 VIN + 0.3

V

EN and MODE Pin Voltage –0.3 VIN + 0.3

CTRL

VFB FB Pin –0.3 4 V

ESD

Electrostatic Discharge Protection Level

Human Body Model per JESD22-A114 3.0

Charged Device Model per JESD22-C101 1.5

TJ Junction Temperature –40 +150 °C

T

Storage Temperature –65 +150 °C

STG

TL Lead Soldering Temperature, 10 Seconds +260 °C

Note:

3. Lesser of 6.5V or VIN+0.3V.

(3)

V

kV

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. Typ. Max. Unit

VCC Supply Voltage Range 2.7

I

OUT

Output Current for 2.1V 0 750

Output Current for 2.5V, 2.7V, 2.9V, 3.3V 0 500

L Inductor 1 µH

CIN Input Capacitor 2.2 µF

C

Output Capacitor 10 24

OUT

TA Operating Ambient Temperature –40 +85 °C

TJ Operating Junction Temperature –40 +125 °C

Note:

= V

4. Minimum V

IN

+ 200mV or 2.7V, whichever is greater.

OUT

(4)

5.5 V

mA

μF

Thermal Properties

Junction-to-ambient thermal resistance is a function of application and board layout. This data is measured with four-layer 1s2p boards in accordance to JEDEC standard JESD51. Special attention must be paid not to exceed junction temperature T

at a given ambient temperature TA.

J(max)

Symbol Parameter Typical Unit

JA

Junction-to-Ambient Thermal Resistance

WLSCP 150

UMLP 49

°C/W

Electrical Characteristics

Minimum and maximum values are at VIN = VEN = 2.7V to 5.5V, V Figure 1, unless otherwise noted. Typical values are at T

= 25°C, VIN = VEN = 3.6V, V

A

Symbol Parameter Conditions Min. Typ. Max. Unit

Power Supplies

IQ Quiescent Current

I

Shutdown Supply Current EN = GND 0.05 1.00 µA

(SD)

V

UVHYST

V

I

V

I

UVLO

(ENH)

(ENL)

(EN)

Under-Voltage Lockout Threshold

Under-Voltage Lockout Hysteresis

Enable HIGH-Level Input Voltage 1.05 V

Enable LOW-Level Input Voltage 0.4 V

Enable Input Leakage Current EN to VIN or GND 0.01 1.00 µA

MODE HIGH-Level Input Voltage 1.05 V

(MH)

MODE LOW-Level Input Voltage 0.4 V

(ML)

MODE Input Leakage Current MODE to VIN or GND 0.01 1.00 µA

(M)

Switching and Synchronization

fSW Switching Frequency

f

MODE Synchronization Range

SYNC

(5)

V

Regulation

2.10V I

2.50V

VO

Output Voltage Accuracy

2.70V, 2.90V,

3.30V

No Load, Not Switching, V

PWM Mode 5 mA

Rising VIN 2.5 2.6 V

175 mV

= 3.6V, TA = 25°C 2.7 3.0 3.3 MHz

IN

(5)

Square Wave at MODE Input 1.3 1.5 1.7 MHz

= 0 to 750mA

LOAD

I

= 0 to 400mA, VIN ≥ V

LOAD

200mV

I

= 0 to 500mA, VIN ≥ V

LOAD

300mV

I

= 0 to 400mA, VIN ≥ V

LOAD

150mV

I

= 0 to 500mA, VIN ≥ V

LOAD

300mV

= 0V (AUTO Mode), TA = -40°C to +85°C; circuit of

MODE

> 3V 45 75 µA

IN

+

OUT

+

OUT

+

OUT

+

OUT

= 0V, C

MODE

2.037 (-3%)

2.375 (-5%)

2.425 (-3%)

=10µF.

OUT

2.100

2.500

2.163

(+3%)

2.575

(+3%)

2.575

(+3%)

-5% +3%

-3% +3%

V

FAN5362 — 3MHz, 500mA / 750mA Synchronous Buck Regulator

tSS Soft-Start From EN Rising Edge 180 300 µs

Output Driver

R

DS(on)

I

LIM(OL)

T

PMOS On Resistance V

NMOS On Resistance VIN = VGS = 3.6V 300

PMOS Peak Current Limit

Thermal Shutdown 150 °C

TSD

Thermal Shutdown Hysteresis 15 °C

HYS

(5)

= VGS = 3.6V 330

IN

V

= 2.1V 1375 mA

OUT

V

= 2.5V, 2.7V, 2.9V, 3.3V 800 1000 1150 mA

OUT

m m

Notes:

5. Limited by the effect of t

minimum (see Figure 8 in Typical Performance Characteristics).

OFF

6. The Electrical Characteristics table reflects open-loop data. Refer to the Operation Description and Typical Characteristics for closed-loop data.

Typical Characteristics

Unless otherwise noted, VIN=VEN=3.6V,V

=0 (AUTO), V

MODE

=2.9V, C

OUT

=10µF, and TA=25°C.

OUT

FAN5362 — 3MHz, 500mA / 750mA Synchronous Buck Regulator

100%

2.910

98%

96%

2.905

94%

92%

2.900

90%

2.895

88%

Efficiency

86%

84%

82%

80%

1 10 100 1000

I

Output Current (mA)

LOAD

VIN = 3.2, M ode=0

VIN = 3.6, M ode=0

VIN = 4.2, M ode=0

VIN = 3.2, M ode=1

VIN = 3.6, M ode=1

VIN = 4.2, M ode=1

VOUT (V)

2.890

Auto 3.6VIN

Auto 3.2VIN

2.885

- 100 200 300 400 500

I

Output Current (mA)

LOAD

Figure 5. Efficiency vs. Load Current and Input Supply Figure 6. Load Regulation

90

80

70

60

)

50

40

ripple(mVpp

VOUT

30

20

10

3.2VIN_Auto

3.6VIN_AUTO

0

0 100 200 300 400 500

Loadcurrent(mA)

Figure 7. Ripple Figure 8. Effect of t

3500

3000

2500

2000

1500

1000

SwitchingFrequency(kHz)

500

0

0 50 100 150 200 250 300 350 400 450 500

LoadCurrent(mA)

on Reducing Switching

OFF(MIN)

3.2VIN_AUTO

3.6VIN_AUTO

3.6VIN_FPWM

3.2VIN_FPWM

Frequency

1300

500

100

%

450

.

d.c

400

350

300

250

200

150

100

Load Curr ent (mA)

50

Hysteresis

0

33.544.555.5

Always PWM

Always PFM

Input Volt age(V)

1200

1100

1000

900

800

PeakIn ductorCurrent(mA)

700

600

2.53.03.54.04.55.05.5

InputVol tage(V)

‐40C

+25C

+85C

Figure 9. PFM / PWM Boundaries Figure 10. Peak Inductor Current