FAN5350MPX - Fairchild Semiconductor Corporation

March 2010

FAN5350 Rev. 1.0.5

FAN5350 — 3MHz, 600mA Step-Down DC-DC Converter in Chip-Scale and MLP Packaging

FAN5350

3MHz, 600mA Step-Down DC-DC Converter in

Chip-Scale and MLP Packaging

Features

 3MHz Fixed-Frequency Operation

 16µA Typical Quiescent Current

 600mA Output Current Capability

 2.7V to 5.5V Input Voltage Range

 1.82V Fixed Output Voltage

 Synchronous Operation

 Power-Save Mode

 Soft-Start Capability

 Input Under-Voltage Lockout (UVLO)

 Thermal Shutdown and Overload Protection

 6-Lead 3 x 3mm MLP

 5-Bump 1 x 1.37mm WLCSP

Applications

 Cell Phones, Smart-Phones

 Pocket PCs

 WLAN DC-DC Converter Modules

 PDA, DSC, PMP, and MP3 Players

 Portable Hard Disk Drives

Description

The FAN5350 is a step-down switching voltage

regulator that delivers a fixed 1.82V from an input

voltage supply of 2.7V to 5.5V. Using a proprietary

architecture with synchronous rectification, the

FAN5350 is capable of delivering 600mA at over 90%

efficiency, while maintaining a very high efficiency of

over 80% at load currents as low as 1mA. The regulator

operates at a nominal fixed frequency of 3MHz at full

load, which reduces the value of the external

components to 1µH for the output inductor and 4.7µF

for the output capacitor.

At moderate and light loads, pulse frequency

modulation is used to operate the device in power-save

mode with a typical quiescent current of 16µA. 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.

The FAN5350 is available in a 6-lead Molded Leadless

Package (MLP) and a 5-bump Wafer Level Chip Scale

Package (WLCSP).

Ordering Information

Part Number Operating

Temperature Range Package Eco

Status Packing Method

FAN5350UCX -40°C to 85°C 5-Ball, Type-1 WL-CSP, 1x1.37mm,

.5mm Pitch Green Tape and Reel

FAN5350MPX -40°C to 85°C

6-Lead, Molded Leadless Package

(MLP), Dual, JEDEC MO-229, 3mm

Square, Extended DAP

Green Tape and Reel

For Fairchild’s defini t i on of Eco St atus, pleas e visit: http://www.fairchildsemi.com/company/green/rohs_green.html.

Please ref er to tape and reel spec i fications at www.fairchildsemi.com; http://www.fairchildsemi.com/packaging.

FAN5350 Rev. 1.0.5 2

FAN5350 — 3MHz, 600mA Step-Down DC-DC Converter in Chip-Scale and MLP Packaging

Typical Applications

4.7µF

OUT

C1 C3

VIN

GND

1µH

4.7µF

AGND

VIN

PGND

1 6

2 5

3 4

OUT

(GND)

1µΗ

.7µF

4.7µF

Figure 1. WLCSP, Bumps Facing Down Figure 2. MLP, Leads Facing Down

Block Diagram

GND

VIN

1.8V

Reference

Modulator Logic Driver

Current Limit

Zero Crossing

3MHz OSC

Bias

Figure 3. Block Diagram

FAN5350 Rev. 1.0.5 3

FAN5350 — 3MHz, 600mA Step-Down DC-DC Converter in Chip-Scale and MLP Packaging

Pin Configurations

C1 C3

VIN

GND

A3 A1

C3 C1

GND

VIN

Figure 4. WLCSP - Bumps Facing Down Figure 5. WLCSP - Bumps Facing Up

AGND

VINPGND

1 6

2 5

3 4

(GND)

Figure 6. 3x3mm MLP - Leads Facing Down

Pin Definitions

WLCSP

Pin # Name Description

A1 VIN Power Supply Input.

A3 GND

Ground Pin. Signal and power ground for the part.

C1 EN

Enable Pin. 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.

C3 FB

Feedback Analog Input. Connect directly to the output capacitor.

B2 SW

Switching Node. Connection to the internal PFET switch and NFET synchronous rectifier.

MLP

Pin # Name Description

1 PGND

Power Ground Pin. Power stage ground. Connect PGND and AGND together via the board

ground plane.

2 AGND

Analog Ground Pin. Signal ground for the part.

3 FB

Feedback Analog Input. Connect directly to the output capacitor.

4 EN

Enable Pin. 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.

5 SW

Switching Node. Connection to the internal PFET switch and NFET synchronous rectifier.

6 VIN Power Supply Input.

FAN5350 Rev. 1.0.5 4

FAN5350 — 3MHz, 600mA Step-Down DC-DC Converter in Chip-Scale and MLP Packaging

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 with respect to GND -0.3 6.0 V

Voltage on any other pin with respect to GND -0.3 VIN V

TJ Junction Temperature -40 +150 °C

TSTG Storage Temperature -65 +150 °C

TL Lead Temperature (Soldering 10 Seconds) +260 °C

ESD Electrostatic Discharge

Protection Level

Human Body Model 4.5

Charged Device Model MLP 1.5

WLCSP 2.0

Machine Model 200 V

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 5.5 V

IOUT Output Current 0 600 mA

L Inductor 0.7 1.0 3.0 µH

CIN Input Capacitor 3.3 4.7 12.0 µF

COUT Output Capacitor 3.3 4.7 12.0 µF

TA Operating Ambient Temperature -40 +85 °C

TJ Operating Junction Temperature -40 +125 °C

Thermal Properties

Symbol Parameter Min. Typ. Max. Units

ΘJA_WLCSP Junction-to-Ambient Thermal Resistance(1) 180 °C/W

ΘJA_MLP Junction-to-Ambient Thermal Resistance(1) 49 °C/W

Note:

1. 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 JESD51- JEDEC standard. Special attention must be paid not to

exceed junction temperature TJ(max) at a given ambient temperate TA.

FAN5350 Rev. 1.0.5 5

FAN5350 — 3MHz, 600mA Step-Down DC-DC Converter in Chip-Scale and MLP Packaging

Electrical Characteristics

Minimum and maximum values are at VIN = 2.7V to 5.5V, TA = -40°C to +85°C, CIN = COUT = 4.7µF, L = 1µH, unless

otherwise noted. Typical values are at TA = 25°C, VIN =3.6V.

Symbol Parameter Conditions Min. Typ. Max. Units

Power Supplies

IQ Quiescent Current

Device is not switching, EN=VIN 16 µA

Device is switching, EN=VIN 18 25 µA

I(SD) Shutdown Supply Current VIN = 3.6V, EN = GND 0.05 1.00 µA

VUVLO Under-Voltage Lockout Threshold

Rising Edge 1.8 2.1

Falling Edge 1.75 1.95

V(ENH) Enable HIGH-Level Input Voltage 1.2 V

V(ENL) Enable LOW-Level Input Voltage 0.4 V

I(EN) Enable Input Leakage Current EN = VIN or GND 0.01 1.00 µA

Oscillator

f0SC Oscillator Frequency 2.5 3.0 3.5 MHz

Regulation

VO Output Voltage Accuracy

ILOAD = 0 to 600mA 1.775 1.820 1.865 V

CCM 1.784 1.820 1.856 V

tSS Soft-Start EN = 0 -> 1 300 µs

Output Driver

RDS(on)

PMOS On Resistance VIN = VGS = 3.6V 180 mΩ

NMOS On Resistance VIN = VGS = 3.6V 170 mΩ

ILIM PMOS Peak Current Limit Open-Loop(2) 650 800 900 mA

TTSD Thermal Shutdown CCM Only 150 °C

THYS Thermal Shutdown Hysteresis 20 °C

Note:

2. The Electrical Characteristics table reflects open-loop data. Refer to Operation Description and Typical

Characteristic for closed-loop data.

FAN5350 Rev. 1.0.5 6

FAN5350 — 3MHz, 600mA Step-Down DC-DC Converter in Chip-Scale and MLP Packaging

Operation Description

The FAN5350 is a step-down switching voltage regulator

that delivers a fixed 1.82V from an input voltage supply of

2.7V to 5.5V. Using a proprietary architecture with

synchronous rectification, the FAN5350 is capable of

delivering 600mA at over 90% efficiency, while

maintaining a light load efficiency of over 80% at load

currents as low as 1mA. The regulator operates at a

nominal frequency of 3MHz at full load, which reduces the

value of the external components to 1µH for the output

inductor and 4.7µF for the output capacitor.

Control Scheme

The FAN5350 uses a proprietary non-linear, fixed-

frequency PWM modulator to deliver a fast load

transient response, while maintaining a constant

switching frequency over a wide range of operating

conditions. The regulator performance is independent of

the output capacitor ESR, allowing for the use of

ceramic output capacitors. Although this type of

operation normally results in a switching frequency that

varies with input voltage and load current, an internal

frequency loop holds the switching frequency constant

over a large range of input voltages and load currents.

For very light loads, the FAN5350 operates in

discontinuous current (DCM) single-pulse PFM mode,

which produces low output ripple compared with other

PFM architectures. Transition between PWM and PFM

is seamless, with a glitch of less than 14mV at VOUT

during the transition between DCM and CCM modes.

Combined with exceptional transient response

characteristics, the very low quiescent current of the

controller (<16µA) maintains high efficiency, even at

very light loads, while preserving fast transient response

for applications requiring very tight output regulation.

Enable and Soft Start

Maintaining the EN pin LOW keeps the FAN5350 in

non-switching mode in which all circuits are off and the

part draws ~50nA of current. Increasing EN above its

threshold voltage activates the part and starts the soft-

start cycle. During soft start, the current limit is

increased in discrete steps so that the inductor current

is increased in a controlled manner. This minimizes any

large surge currents on the input and prevents any

overshoot of the output voltage.

Under-Voltage Lockout

When EN is high, the under-voltage lock-out keeps the

part from operating until the input supply voltage rises

high enough to properly operate. This ensures no

misbehavior of the regulator during start-up or shutdown.

Current Limiting

A heavy load or short circuit on the output causes the

current in the inductor to increase until a maximum

current threshold is reached in the high-side switch.

Upon reaching this point, the high-side switch turns off,

preventing high currents from causing damage.

The peak current limit shown in Figure 16, ILIM(PK) is

slightly higher than the open-loop tested current limit,

ILIM(OL), in the Electrical Characteristics table. This is

primarily due to the effect of propagation delays of the

IC current limit comparator.

Thermal Shutdown

When the die temperature increases, due to a high load

condition and/or a high ambient temperature, the output

switching is disabled until the temperature on the die

has fallen sufficiently. The junction temperature at

which the thermal shutdown activates is nominally

150°C with a 20°C hysteresis.

FAN5350 Rev. 1.0.5 7

FAN5350 — 3MHz, 600mA Step-Down DC-DC Converter in Chip-Scale and MLP Packaging

Applications Information

Selecting the Inductor

The output inductor must meet both the required

inductance and the energy handling capability of the

application.

The inductor value affects the average current limit, the

PWM-to-PFM transition point, the output voltage ripple,

and the efficiency.

The ripple current (∆I) of the regulator is:

⎟

⎠

⎞

⎜

⎝

⎛

•

−

•≈Δ

OUTIN

OUT

I (1)

The maximum average load current, IMAX(LOAD) is related

to the peak current limit, ILIM(PK) (see figure 17) by the

ripple current:

II )PK(LIM)LOAD(MAX

−= (2)

The transition between PFM and PWM operation is

determined by the point at which the inductor valley

current crosses zero. The regulator DC current when

the inductor current crosses zero, IDCM, is:

IDCM

= (3)

The FAN5350 is optimized for operation with L=1μH,

but is stable with inductances ranging from 700nH to

3.0μH. The inductor should be rated to maintain at least

80% of its value at ILIM(PK).

Efficiency is affected by the inductor DCR and

inductance value. Decreasing the inductor value for a

given physical size typically decreases the DCR; but

since ∆I increases, the RMS current increases, as do

the core and skin effect losses.

I I

)DC(OUTRMS

+= (4)

The increased RMS current produces higher losses

through the RDS(ON) of the IC MOSFETs as well as the

inductor ESR.

Increasing the inductor value produces lower RMS

currents, but degrades transient response. For a given

physical inductor size, increased inductance usually

results in an inductor with lower saturation current.

Table 1 shows the effects of inductance higher or lower

than the recommended 1μH on regulator performance.

Output Capacitor

Table 2 suggests 0603 capacitors. 0805 capacitors may

further improve performance in that the effective

capacitance is higher and ESL is lower than 0603. This

improves the transient response and output ripple.

Increasing COUT has no effect on loop stability and can

therefore be increased to reduce output voltage ripple

or to improve transient response. Output voltage ripple,

∆VOUT, is:

⎟

⎠

⎞

⎜

⎝

⎛+

••

•Δ=Δ ESR

FC8

SWOUT

OUT (5)

Input Capacitor

The 4.7μF ceramic input capacitor should be placed as

close as possible between the VIN pin and GND to

minimize the parasitic inductance. If a long wire is used

to bring power to the IC, additional “bulk” capacitance

(electrolytic or tantalum) should be placed between CIN

and the power source lead to reduce ringing that can

occur between the inductance of the power source

leads and CIN.

Table 1. Effects of changes in inductor value (from 1µH recommended value) on regulator performance

Inductor Value IMAX(LOAD) EQ. 2 ILIM(PK) ∆VOUT EQ. 5 Transient Response

Increase Increase Decrease Decrease Degraded

Decrease Decrease Increase Increase Improved

FAN5350 Rev. 1.0.5 8

FAN5350 — 3MHz, 600mA Step-Down DC-DC Converter in Chip-Scale and MLP Packaging

PCB Layout Guidelines

For the bill of materials of the FAN5350 evaluation

board, see Table 1. There are only three external

components: the inductor and the input and output

capacitors. For any buck switcher IC, including the

FAN5350, it is always important to place a low-ESR

input capacitor very close to the IC, as shown in Figure

7. That ensures good input decoupling, which helps

reduce the noise appearing at the output terminals and

ensures that the control sections of the IC do not

behave erratically due to excessive noise. This reduces

switching cycle jitter and ensures good overall

performance. It is not considered critical to place either

the inductor or the output capacitor very close to the IC.

There is some flexibility in moving these two

components further away from the IC.

Table 2. FAN5350 Evaluation Board Bill of Materials (optional parts are installed by request only)

Figure 7. The FAN5350 Evaluation Board PCB (CSP)

Feedback Loop

One key advantage of the non-linear architecture is that

there is no traditional feedback loop. The loop response

to changes in VOUT is essentially instantaneous, which

explains its extraordinary transient response. The

absence of a traditional, high-gain compensated linear

loop means that the FAN5350 is inherently stable over

a wide range of LOUT and COUT.

LOUT can be reduced further for a given application,

provided it is confirmed that the calculated peak current

for the required maximum load current is less than the

minimum of the closed-loop current limit. The

advantage is that this generally leads to improved

transient response, since a small inductance allows for

a much faster increase in current to cope with any

sudden load demand.

The inductor can be increased to 2.2µH; but, for the

same reason, the transient response gets slightly

degraded. In that case, increasing the output capacitor

to 10µF helps significantly.

Description Qty. Ref. Vendor Part Number

Inductor

1.2μH, 1.8A, 55mΩ

1 L1

TOKO 1117AS-1R2M

1.3μH, 1.2A, 90mΩ FDK MIPSA2520D1R0

1.5μH, 1.3A Taiyo Yuden CBC3225T15MR

Capacitor 4.7μF, ±10%, 6.3V, X5R, 0603 2 CIN,COUT MURATA GRM39 X5R 475K 6.3

IC DC/DC Regulator in CSP, 5 bumps 1 U1 Fairchild FAN5350UCX

Load Resistor (Optional) 1 RLOAD Any

FAN5350 Rev. 1.0.5 9

FAN5350 — 3MHz, 600mA Step-Down DC-DC Converter in Chip-Scale and MLP Packaging

Typical Performance Characteristics

VIN = 3.6V, TA = 25°C, VEN = VIN, according to the circuit in Figure 1 or Figure 2, unless otherwise specified.

2.5 3.0 3.5 4.0 4.5 5.0 5.5

Battery Voltage (V)

Quiescent Current (µA)

-40°C

+85°C

+25°C

1790

1800

1810

1820

1830

1840

1850

0 100 200 300 400 500 600

Load Current (m A)

DC Output Voltage (mV)

DCM spreading

CCM

Figure 8. Quiescent Current vs. Battery Voltage Figure 9. Load Regulation, Increasing Load

100

200

300

400

500

600

2.5 3.0 3.5 4.0 4.5 5.0 5.5

Load Current (mA)

Continuous Conduction Mode

Discontinuous Conduction Mode

Hysteresis

Battery Voltage (V)

Switching mode

changes at these

borders

85°C CCM border

85°C DCM border

-30°C DCM border

-30°C CCM border

100

200

300

400

500

600

2.5 3.0 3.5 4.0 4.5 5.0 5.5

Load Current (mA)

Battery Voltage (V)

Figure 10. Switch Mode Operating Areas Figure 11. Switch Mode Over Temperature

2.00

1.75

1.50

1.25

1.00

0.75

0.50

0.25

0 0.1 0.2 0.3 0.4 0.5 0 .6 0.7 0.8 0.9 1.0 1.1

Load Current (A)

Output Voltage (V)

=5.5V

=3.6V

=2.7V

Ambient Temperature (°C)

Output Voltage (mV)

1800

1805

1810

1815

1820

1825

1830

1835

=5.5V

=3.6V

=2.7V

-40-200 20406080

LOAD

=300mA

Figure 12. DC Current Voltage Output Characteristics Figure 13. Output Voltage vs. Temperature

FAN5350 Rev. 1.0.5 10

FAN5350 — 3MHz, 600mA Step-Down DC-DC Converter in Chip-Scale and MLP Packaging

Typical Performance Characteristics (Continued)

VIN = 3.6V, TA = 25°C, VEN = VIN, according to the circuit in Figure 1 or Figure 2, unless otherwise specified.

100

0.001 0.010 0.100 1.000

Power Efficiency (%)

=2.5V

=2.7V

=3.3V

=3.6V

=4.2V

=5V

=5.5V

Load Current (A)

100

0.001 0.010 0.100 1.000

Power Efficiency (%)

Load Current (A)

+85°C

+25°C

-40°C

Figure 14. Power Efficiency vs. Load Current Figure 15. Power Efficiency Over Temperature Range

1.3

1.2

1.1

1.0

0.9

0.8

0.7

-40-20 0 20406080

Ambient Temperature (°C)

Current Limit (A)

=5.5V

=2.7V

=3.6V

100

150

200

250

2.53.03.54.04.55.05.5

Shutdown Current (nA)

Battery Voltage (V)

+85°C

+25°C

-40°C

Figure 16. PMOS Current Limit in Closed Loop Figure 17. Shutdown Supply Current vs.

Battery Voltage

85dB

5dB

/div

35dB

250mA Load

1Hz 10Hz 100Hz 1kHz 10kHz

2.7

2.8

2.9

3.0

3.1

3.2

3.3

2.7 2.9 3.1 3.3 3.5 3.7 3.9 4.1 4.3 4.5 4.7 4.9 5.1 5.3 5.5

Frequency (MHz)

Battery Voltage (V)

-40°C

+85°C

+25°C

Figure 18. Power Supply Rejection Ratio in CCM Figure 19. Switching Frequency in CCM

FAN5350 Rev. 1.0.5 11

FAN5350 — 3MHz, 600mA Step-Down DC-DC Converter in Chip-Scale and MLP Packaging

, 0.5A / div.

OUT

, 0.5V / div.

EN, 5.0V / div.

, 0.5A / div.

OUT

, 0.5V / div.

EN, 5.0V / div.

LOAD

, 0.5A / div.

OUT(ac)

, 20mV / div.

LOAD

, 0.5A / div.

OUT(ac)

, 20mV / div.

LOAD

= 600mA

OUT(ac)

, 20mV / div.

LOAD

= 300mA

, 5V / div.

LOAD

= 50mA

OUT(ac)

, 20mV / div.

LOAD

= 1mA

, 5V / div.

H scale: 20µs / div. H scale: 10µs / div.

H scale: 1µs / div. H scale: 1µs / div.

H scale: 20µs / div. H scale: 20µs / div.

Typical Performance Characteristics (Continued)

VIN = 3.6V, TA = 25°C, VEN = VIN, according to the circuit in Figure 1 or Figure 2, unless otherwise specified.

Figure 20. Startup, Full Load Figure 21. Startup, No Load

Figure 22. Fast Load Transient, No Load to Full Load Figure 23. Fast Load Transient, Full Load to No Load

Figure 24. Fast Load Transient in CCM Figure 25. Fast Load Transient in DCM

FAN5350 Rev. 1.0.5 12

FAN5350 — 3MHz, 600mA Step-Down DC-DC Converter in Chip-Scale and MLP Packaging

LOAD

, 0.5A / div.

OUT

, 20mV / div.

OUT(ac)

, 20mV / div. V

OUT(ac)

, 20mV / div.

OUT(ac)

, 20mV / div.

= 0.2A / div.

, 2V / div.

OUT(ac)

, 20mV / div.

= 0.1A / div.

, 2V / div.

= 3.6V

= 3.0V

= 3.6V

= 3.0V

, 2V / div.

LOAD

= 300mA

OUT

, 20mV / div.

, 5V / div.

LOAD

= 20mA

H scale: 20µs / div. H scale: 2ms / div.

H scale: 10µs / div. H scale: 10µs / div.

H scale: 1µs / div. H scale: 200ns / div.

LOAD

= 350mA

OUT(ac)

, 10mV / div.

LOAD

= 100mA

= 3.0V

= 3.6V

H scale: 5µs / div.

Typical Performance Characteristics (Continued)

VIN = 3.6V, TA = 25°C, VEN = VIN, according to the circuit in Figure 1 or Figure 2, unless otherwise specified.

Figure 26. Fast Load Transient DCM – CCM – DCM Figure 27. Slow Load Transient DCM – CCM – DCM

Figure 28. Line Transient, 600mV, 50mA Load Figure 29. Line Transient, 600mV, 50mA Load

Figure 30. Combined Line (600mV) and Load (100mA to 350mA) Transient Response

Figure 31. Typical Waveforms in DCM, 50mA Load Figure 32. Typical Waveforms in CCM, 150mA Load

FAN5350 Rev. 1.0.5 13

FAN5350 — 3MHz, 600mA Step-Down DC-DC Converter in Chip-Scale and MLP Packaging

Physical Dimensions

B. DIMENSIONS ARE IN MILLIMETERS.

C. DIMENSIONS AND TOLERANCES PER

A. CONFORMS TO JEDEC REGISTRATION MO-229,

VARIATION WEEA, DATED 11/2001

ASME Y14.5M, 1994

0.10 CAB

0.05 C

TOP VIEW

BOTTOM VIEW

RECOMMENDED LAND PATTERN

0.15 C

0.08 C

3.0

0.05

0.00

2.25

1.65

1.90

0.15 C

0.45

0.20

0.8 MAX

SIDE VIEW

SEATING

PLANE

2.45

0.95 TYP

0.10 C

PIN #1 IDENT

(0.70)

0.30~0.45

0.2 MIN

0.95

2.10

3.50

0.45 TYP

(0.20)

PIN #1 IDENT

EXCEPT FOR DAP EXTENSION TABS

3.50

0.40

0.45

1.65

Figure 33. 6-Lead Molded Leadless Package (MLP)

Pack age drawings are provided as a service to customers consideri ng Fai rchild components . Drawings may c hange i n any manner

without notice. P l ease note the revi sion and/or date on t he drawing and contac t a Fairchild S emiconductor representative to verify

or obtain the most recent revi sion. Pac kage specif i cations do not expand the terms of Fai rchild’s worldwi de terms and condition s,

specifically the warranty t herei n, which covers Fairc hi l d products.

Always vis i t Fairchild S emiconductor’s online packaging area for the most recent package drawings:

http://www.fairchildsemi.com/packaging/.

FAN5350 Rev. 1.0.5 14

FAN5350 — 3MHz, 600mA Step-Down DC-DC Converter in Chip-Scale and MLP Packaging

Physical Dimensions (Continued)

0.625 MAX

SEATING PLANE

0.06 C

5 X Ø0.315 +/- .025

TOP VIEW

BOTTOM VIEW

(Ø0.35)

SOLDER MASK

OPENING

(Ø0.25)

Cu PAD

RECOMMENDED LAND PATTERN (NSMD)

BALL A1

INDEX AREA

0.03 C

0.05 C

(Y)+/-.018

(X)+/-.018

0.250±0.025

0.03 C

0.005 CAB

0.50

0.433

0.50

(0.50)

(0.433)

(0.866)

0.332±0.018

SIDE VIEWS

B. DIMENSIONS ARE IN MILLIMETERS.

C. DIMENSIONS AND TOLERANCES PER

A. NO JEDEC REGISTRATION APPLIES

ASME Y14.5M, 1994

DDATUM C, THE SEATING PLANE, IS DEFINED

BY THE SPHERICAL CROWNS OF THE BALLS.

EPACKAGE TYPICAL HEIGHT IS 582 MICRONS

+/- 43 MICRONS (539-625 MICRONS)

FOR DIMENSIONS D, E, X, AND Y SEE

PRODUCT DATASHEET.

G. BALL COMPOSITION: Sn95.5Ag3.9Cu0.6

SAC405 ALLOY

H. DRAWING FILENAME: MKT-UC005AArev5

Product Specific Dimensions

Product D E X Y

FAN5350UCX 1.350 +/- 0.040 0.980 +/- 0.040 0.242 0.244

Figure 34. 5-Bump Wafer-Level Chip-Scale Package (WLCSP)

Pack age drawings are provided as a service to customers consideri ng Fai rchild components . Drawings may c hange i n any manner

without notice. P l ease note the revi sion and/or date on t he drawing and contac t a Fairchild S emiconductor representative to verify

or obtain the most recent revi sion. Pac kage specif i cations do not expand the terms of Fai rchild’s worldwi de terms and condition s,

specifically the warranty t herei n, which covers Fairc hi l d products.

Always vis i t Fairchild S emiconductor’s online packaging area for the most recent package drawings:

http://www.fairchildsemi.com/packaging/.

FAN5350 Rev. 1.0.5 15

FAN5350 — 3MHz, 600mA Step-Down DC-DC Converter in Chip-Scale and MLP Packaging