Datasheet FAN4860 Datasheet (Fairchild)

November 2010

FAN4860

3MHz, Synchronous TinyBoost™ Regulator

FAN4860 — 3MHz, Synchronous TinyBoost™ Regulator

Features

Operates with Very Small External Components:



1μH Inductor and 0402 Case Size Input and Output Capacitors

 Input Voltage Range from 2.3V to 4.5V  Fixed 3.3V or 5.0V Output Voltage Options  Maximum Load Current >200mA at V  Maximum Load Current 300mA at V  Maximum Load Current 300mA at V

=2.3V

IN

=3.3V, V

IN

=2.7V, V

IN

OUT

=5V

=3.3V

 Up to 92% Efficient  Low Operating Quiescent Current  True Load Disconnect During Shutdown  Variable On-time Pulse Frequency Modulation (PFM) with

Light-Load Power-Saving Mode

 Internal Synchronous Rectifier

(No External Diode Needed)

 Thermal Shutdown and Overload Protection  6-Pin 2 x 2mm UMLP  6-Bump WLCSP, 0.4mm Pitch

Applications

Description

The FAN4860 is a low-power boost regulator designed to provide a regulated 3.3V or 5V output from a single cell Lithium or Li-Ion battery. Output voltage options are fixed at either 3.3V or 5.0V with a guaranteed maximum load current of 200mA at V in shut-down mode is less than 1µA, which maximizes battery life.

Light-load PFM operation is automatic and “glitch-free”. The regulator maintains output regulation at no-load with as low as 37µA quiescent current.

The combination of built-in power transistors, synchronous rectification, and low supply current make the FAN4860 ideal for battery powered applications.

The FAN4860 is available in 6-bump 0.4mm pitch WaferLevel Chip Scale Package (WLCSP) and a 6-lead 2x2mm ultra-thin MLP package.

=2.3V and 300mA at VIN=3.3V. Input current

IN

 USB “On the Go” 5V Supply  5V Supply – HDMI, H-Bridge Motor Drivers  Powering 3.3V Core Rails  PDAs, Portable Media Players

Figure 1. Typical Application

 Cell Phones, Smart Phones, Portable Instruments

Ordering Information

Part Number Operating Temperature Range Package Packing Method

FAN4860UC5X -40°C to 85°C WLCSP, 0.4mm Pitch Tape and Reel

FAN4860UMP5X -40°C to 85°C UMLP-6, 2 x 2mm Tape and Reel

FAN4860UC33X -40°C to 85°C WLCSP, 0.4mm Pitch Tape and Reel

Please refer to tape and reel specifications at http://www.fairchildsemi.com/packaging.

Block Diagrams

Figure 2. IC Block Diagram

FAN4860 — 3MHz, Synchronous TinyBoost™ Regulator

Pin Configuration

Figure 3. WLCSP (Top View) Figure 4. WLCSP (Bottom View) Figure 5. 2X2mm UMLP (Top View)

Pin Definitions

Pin #

WLCSP UMLP

A1 6 VIN

B1 5 SW

C1 4 EN

C2 3 FB

B2 2 VOUT

A2 1, P1 GND

Name Description

Input Voltage. Connect to Li-Ion battery input power source and input capacitor (C Switching Node. Connect to inductor. Enable. When this pin is HIGH, the circuit is enabled. This pin should not be left floating. Feedback. Output voltage sense point for V Output Voltage. This pin is both the output voltage terminal as well as an IC bias supply. Ground. Power and signal ground reference for the IC. All voltages are measured with

respect to this pin.

. Connect to output capacitor (C

OUT

).

IN

).

FAN4860 — 3MHz, Synchronous TinyBoost™ 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. Units

VIN VIN Pin -0.3 5.5 V

V

VOUT Pin –2 6 V

OUT

VFB FB Pin –2 14 V

VSW SW Node

VEN EN Pin -0.3 5.5 V

ESD

TJ Junction Temperature –40 +150 °C

T

STG

TL Lead Soldering Temperature, 10 Seconds +260 °C

Electrostatic Discharge Protection Level

Storage Temperature –65 +150 °C

DC

Transient: 10ns, 3MHz -1.0 6.5

Human Body Model per JESD22-A114 2

Charged Device Model per JESD22-C101 1

-0.3 5.5 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. Max. Units

VIN Supply Voltage

I

Output Current 200 mA

OUT

TA Ambient Temperature –40 +85 °C

TJ Junction Temperature –40 +125 °C

5.0 V

3.3 V

2.3 4.5 V

OUT

2.5 3.2 V

OUT

Thermal Properties

Junction-to-ambient thermal resistance is a function of application and board layout. This data is measured with four-layer 2s2p boards in accordance to JEDEC standard JESD51. Special attention must be paid not to exceed junction temperature

at a given ambient temperate TA.

T

J(max)

Symbol Parameter Typical Units

θJA

Junction-to-Ambient Thermal Resistance

WLCSP 130 °C/W

UMLP 57 °C/W

FAN4860 — 3MHz, Synchronous TinyBoost™ Regulator

Electrical Specifications

Minimum and maximum values are at VIN=VEN=2.3V to 4.5V (2.5 to 3.2 VIN for 3.3 V Figure 1, unless otherwise noted. Typical values are at T

=25°C, VIN=VEN=3.6V for V

A

Symbol Parameter Conditions Min. Typ. Max. Units

5.0 V

OUT

IIN VIN Input Current

3.3 V

OUT

I

V

LK_OUT

I

LK_RVSR

V

Under-Voltage Lockout VIN Rising 2.2 2.3 V

UVLO

V

UVLO_HYS

V

Enable HIGH Voltage 1.05 V

ENH

V

Enable LOW Voltage 0.4 V

ENL

I

Enable Input Leakage Current 0.01 1

LK_EN

Leakage Current V

OUT

V

to VIN Reverse Leakage

OUT

Under-Voltage Lockout Hysteresis 190 mV

Quiescent: V

Shutdown: EN=0, VIN=3.6V 0.5 1.5

Quiescent: V

Shutdown: EN=0, VIN=2.7V 0.5 1.5

=0, EN=0, VIN≥3V 10 nA

OUT

V

=5V, VIN=3.6V, EN=0

OUT

V

=3.3V, VIN=3V, EN=0

OUT

VIN from 2.3V to 4.5V, I

(1)

VIN from 2.7V to 4.5V, I

VIN from 3.3V to 4.5V, I

(1)

VIN from 2.5V to 3.2V, I

Referred to V

=3.6V, V

V

IN

VIN=2.7V, V

V

=2.3V 200

IN

OUT

VIN=3.3V 300

VIN=3.6V 400

V

=2.5V 250

IN

OUT

VIN=2.7V 300

VIN=3.6V, V

VIN=2.7V, V

VIN=3.6V, V

VIN=2.7V, V

VIN=3.6V, I

VIN=2.7V, I

=3.6V 300

IN

=10mA 150 °C

LOAD

OUT

5.0 V

V

3.3 V

V

Reference Accuracy

REF

t

Off Time

OFF

I

OUT

Maximum Output Current

Output Voltage Accuracy

OUT

Output Voltage Accuracy

OUT

(2)

ISW SW Peak Current Limit

ISS

tSS Soft-Start Time

R

DS(ON)

T

TSD_HYS

Soft-Start Input Peak Current Limit

N-Channel Boost Switch V

P-Channel Sync Rectifier VIN=3.6V 400

Thermal Shutdown I

TSD

(2)

(3)

Thermal Shutdown Hysteresis 30 °C

5.0 V

3.3 V

5.0 V

3.3 V

5.0 V

3.3 V

5.0 V

3.3 V

=3.6V, I

IN

=2.7V, I

IN

=5V 4.975 5.050 5.125

OUT

=3.3V 3.280 3.330 3.380

OUT

=5V, I

OUT

=3.3V, I

OUT

OUT>VIN

< VIN 850

OUT

< VIN 700

OUT

=200mA 100 300

OUT

=200mA 250 750

OUT

=0, EN=V

OUT

=0, EN=V

OUT

≤200mA 4.80 5.05 5.15

OUT

≤200mA 4.85 5.05 5.15

OUT

≤300mA 4.85 5.05 5.15

OUT

≤200mA 3.17 3.33 3.41

OUT

=200mA 195 240 265

OUT

=200mA 240 290 350

OUT

930 1100 1320

650 800 950

Notes:

1. I

from 0 to I

LOAD

; also includes load transient response. V

OUT

Effective capacitance of C

> 1.5μF.

OUT

measured from mid-point of output voltage ripple.

OUT

2. Guaranteed by design and characterization; not tested in production.

3. Elapsed time from rising EN until regulated V

OUT.

option), TA=-40°C to +85°C; circuit of

OUT

=5V, and VIN=VEN=2.7V for V

OUT

37 45

IN

50 65

IN

OUT

2.5

=3.3V.

μA

V

ns

mA

μs

mΩ

FAN4860 — 3MHz, Synchronous TinyBoost™ Regulator

5.0 V

Typical Characteristics

OUT

Unless otherwise specified, circuit per Figure 1, 3.6VIN, TA=25°C.

100

95

90

85

Efficiency (%)

80

75

0 50 100 150 200 250 300

Load Current (mA)

2.5 Vin

3.3 Vin

3.6 Vin

4.5 Vin

Figure 6. Efficiency vs. VIN Figure 7. Efficiency vs. Temperature, 3.6VIN

50

25

0

-25

2.5 Vin

3.3 Vin

3.6 Vin

4.5 Vin

95

92

89

Efficiency (%)

86

83

80

0 50 100 150 200 250 300

Load Current (mA)

50

25

0

-25

-40C

+25C

+85C

-40C

+25C

+85C

-50

VOUT - 5.05V (mV)

-75

-100 0 50 100 150 200 250 300

Load Current (mA)

Figure 8. Line and Load Regulation Figure 9. Load Regulation vs. Temperature, 3.6V

4000

3200

2400

1600

Frequency (KHz)

800

0

0 50 100 150 200 250 300

Load Current (mA)

Figure 10. Switching Frequency Figure 11. Quiescent Current

2.5 Vin

3.6 Vin

4.5 Vin

-50

VOUT - 5.05V (mV)

-75

-100 0 50 100 150 200 250 300

Load Current (mA)

IN

50

45

40

35

Quiescent Current (uA)

30

25

2.0 2.5 3.0 3.5 4.0 4.5 5.0

Input Voltage(V)

-40C

+25C

+85C

FAN4860 — 3MHz, Synchronous TinyBoost™ Regulator

5.0 V

Unless otherwise specified, circuit per Figure 1, 3.6VIN, TA=25°C.

Typical Characteristics

OUT

Figure 12. Maximum DC Load Current Figure 13. Peak Inductor Current

Figure 14. Output Ripple, 10mA PFM Load Figure 15. Output Ripple, 200mA PWM Load

Figure 16. 0-50mA Load Transient, 100ns Step Figure 17. 50-200mA Load Transient, 100ns Step

FAN4860 — 3MHz, Synchronous TinyBoost™ Regulator

5.0 V

Unless otherwise specified, circuit per Figure 1, 3.6VIN, TA=25°C.

Typical Characteristics

OUT

Figure 18. Line Transient, 5mA Load, 10µs Step Figure 19. Line Transient, 200mA Load, 10µs Step

Figure 20. Startup, No Load

Figure 22. Shutdown, 1KΩ Load Figure 23. Shutdown, 33Ω Load

Figure 21. Startup, 33Ω Load

FAN4860 — 3MHz, Synchronous TinyBoost™ Regulator

5.0 V

Unless otherwise specified, circuit per Figure 1, 3.6VIN, TA=25°C.

Typical Characteristics

OUT

Figure 24. Overload Protection Figure 25. Short-Circuit Response

FAN4860 — 3MHz, Synchronous TinyBoost™ Regulator

3.3 V

Typical Characteristics

OUT

Unless otherwise specified, circuit per Figure 1, 3.0VIN, TA=25°C.

100

95

90

85

Efficiency (%)

80

75

0 50 100 150 200 250 300

Load Current (mA)

2.5 Vin

2.7 Vin

3.0 Vin

3.2 Vin

Figure 26. Efficiency vs. VIN Figure 27. Efficiency vs. Temperature, 3.0VIN

40

20

0

-20

2.5 Vin

2.7 Vin

3.0 Vin

3.2 Vin

98

95

92

89

Efficiency (%)

86

83

0 50 100 150 200 250 300

Load Current (mA)

40

20

0

-20

-40C

+25C

+85C

-40C

+25C

+85C

-40

VOUT - 3.33V (mV)

-60

-80 0 50 100 150 200 250 300

Load Current (mA)

Figure 28. Line and Load Regulation Figure 29. Load Regulation vs. Temperature, 3.0V

55

50

45

40

Quiescent Current (uA)

35

30

2.0 2.3 2.6 2.9 3.2 3.5

Input Voltage(V)

Figure 30. Quiescent Current Figure 31. Maximum DC Load Current

-40C

+25C

+85C

-40

VOUT - 3.33V (mV)

-60

-80 0 50 100 150 200 250 300

Load Current (mA)

700

600

500

400

300

Maximum DC Load Current (mA)

200

2.0 2.3 2.6 2.9 3.2 3.5

Input V ol tage(V)

IN

-40C

+25C

+85C

FAN4860 — 3MHz, Synchronous TinyBoost™ Regulator

3.3 V

Unless otherwise specified, circuit per Figure 1, 3.0VIN, TA=25°C.

Typical Characteristics

OUT

Figure 32. Output Ripple, 10mA PFM Load Figure 33. Output Ripple, 200mA PWM Load

Figure 34. Startup, No Load

Figure 35. Startup, 22Ω Load

Functional Description

FAN4860 — 3MHz, Synchronous TinyBoost™ Regulator

Circuit Description

FAN4860 is a synchronous boost regulator, typically operating at 3MHz in continuous conduction mode (CCM), which occurs at moderate to heavy load current and low V

voltages.

IN

At light-load currents, the converter switches automatically to power-saving PFM mode. The regulator automatically and smoothly transitions between quasi-fixed-frequency continuous conduction PWM mode and variable-frequency PFM mode to maintain the highest possible efficiency over the full range of load current and input voltage.

PWM Mode Regulation

The FAN4860 uses a minimum on-time and computed minimum off-time to regulate V excellent transient response by employing current mode modulation. This technique causes the regulator output to exhibit a load line. During PWM mode, the output voltage drops slightly as the input current rises. With a constant V this appears as a constant output resistance.

The “droop” caused by the output resistance when a load is applied allows the regulator to respond smoothly to load transients with negligible overshoot.

700

600

500

400

300

Output Resistance (mΩ)

200

100

2.0 2.5 3.0 3.5 4.0 4.5 5.0

Input Voltage (V )

Figure 36. Output Resistance (

as a function of I

V

OUT

LOAD

regulator is in PWM mode (continuous conduction) as:

IR05.5V •−=

LOADOUTOUT

For example, at VIN=3.3V, and I drop to:

=200mA, V

LOAD

=•−=

OUT

At V

OUT

IN

=2.3V, and I

. The regulator achieves

OUT

IN

3.3 Vout

5.0 Vout

)

ROUT

can be computed when the

(1)

=200mA, V

LOAD

V974.42.038.005.5V

would drop to:

OUT

V914.42.068.005.5V

would

OUT

(1A)

(1B)

,

PFM Mode

If V

> V

OUT

regulator enters PFM mode. Boost pulses are inhibited until

< V

V

OUT

the output to pump up sufficiently with each PFM boost pulse. Therefore, the regulator behaves like a constant ontime regulator, with the bottom of its output voltage ripple at

5.05V in PFM mode.

Table 1. Operating States

Mode Description Invoked When:

LIN Linear Startup VIN > V

SS Boost Soft-Start V

BST Boost Operating Mode V

Shutdown and Startup

If EN is LOW, all bias circuits are off and the regulator is in shutdown mode. During shutdown, true load disconnect between battery and load prevents current flow from V

, as well as reverse flow from V

V

OUT

LIN State

When EN rises, if VIN > UVLO, the regulator first attempts to bring V

OUT

current source from VIN (I 630mA during LIN1 mode.

If V

reaches VIN-1V during LIN1 mode, the SS state is

OUT

initiated. Otherwise, LIN1 times out after 16 CLK counts and the LIN2 mode is entered.

In LIN2 mode, the current source is incremented to 850mA.

fails to reach VIN-1V after 64 CLK counts, a fault

If V

OUT

condition is declared.

SS State

Upon the successful completion of the LIN state (V 1V), the regulator begins switching with boost pulses current limited to about 50% of nominal level, incrementing to full scale over a period of 32 CLK counts.

If the output fails to achieve 90% of its setpoint within 96 CLK counts at full-scale current limit, a fault condition is declared.

BST State

This is the normal operating mode of the regulator. The regulator uses a minimum t

scheme. Minimum t the regulator’s switching frequency reasonably constant in CCM. t

ON(MIN)

current reaches 0 before t

To ensure that V regulation point, the boost switch remains off as long as FB > V

REF

when the minimum off-time has ended, the

REF

. The minimum on-time is increased to enable

REF

OUT

< V

REG

IN

OUT

OUT=VREG

to VIN.

within about 1V of VIN by using the internal fixed

). The current is limited to about

LIN1

OUT>VIN

-minimum tON modulation

OFF

is proportional to , which keeps

OFF

V

IN

OUT

is proportional to VIN and is higher if the inductor

during the prior cycle.

OFF(MIN)

does not pump significantly above the

OUT

.

to

-

Fault State

The regulator enters the FAULT state under any of the following conditions:

 V

fails to achieve the voltage required to advance from

OUT

LIN state to SS state.

 V

fails to achieve the voltage required to advance from

OUT

SS state to BST state.

 Sustained (32 CLK counts) pulse-by-pulse current limit

during the BST state.

 The regulator moves from BST to LIN state due to a short

circuit or output overload (V

Once a fault is triggered, the regulator stops switching and presents a high-impedance path between V waiting 480 CLK counts, a re-start is attempted.

Soft-Start and Fault Timing

The soft-start timing for each state, and the fault times, are determined by the fault clock, whose period is inversely proportional to V charge larger values of C

, this also reduces power delivered to V

V

IN

cycle in current limit.

The number of clock counts for each state is illustrated in Figure 37.

. This allows the regulator more time to

IN

< VIN-1V).

OUT

and V

IN

when VIN is lower. With higher

OUT

during each

OUT

. After

The fault clock period as a function of V

Figure 38. Fault Clock Period vs. VIN

The V

-dependent LIN mode charging current is illustrated

IN

in Figure 39.

is shown in Figure 38.

IN

FAN4860 — 3MHz, Synchronous TinyBoost™ Regulator

Figure 39. LIN Mode Current vs. V

IN

Figure 37. Fault Response into Short Circuit

Over-Temperature Protection (OTP)

The regulator shuts down when the thermal shutdown threshold is reached. Restart, with soft-start, occurs when the IC has cooled by about 30°C.

Over-Current Protection (OCP)

During boost-mode operation, the FAN4860 employs a cycle-by-cycle peak current limit to protect switching elements. Sustained current limit, for 32 consecutive fault CLK counts, initiates a fault condition.

During an overload condition, as V approximately V

-1V, the synchronous rectifier is

IN

immediately switched off and a fault condition is declared. Automatic restart occurs once the overload/short is removed

and the fault timer completes counting.

collapses to

OUT

Application Information

FAN4860 — 3MHz, Synchronous TinyBoost™ Regulator

External Component Selection

Table 2 shows the recommended external components for the FAN4860:

Table 2. External Components

REF Description Manufacturer

1.0µH, 0.8A, 190mΩ,

L1

0805

2.2µF, 6.3V, X5R,

CIN

0402

4.7µF, 10V, X5R,

C

0603

(4)

OUT

Note:

4. A 6.3V-rated 0603 capacitor may be used for C such as Murata GRM188R60J225M. All datasheet parameters are valid with the 6.3V-rated capacitor. Due to DC bias effects, the 10V capacitor offers a performance enhancement; particularly output ripple and transient response, without any size increase.

Output Capacitance (C

Stability

The effective capacitance (C ceramic capacitors decrease as their bias voltage increases, as shown in Figure 40.

Figure 40. C

FAN4860 is guaranteed for stable operation with the minimum value of C

for 4.7μF, 0603, X5R, 6.3V (Murata

EFF

(C

EFF

Murata LQM21PN1R0MC0, or equivalent

Murata GRM155R60J225M

TDK C1005X5R0J225M

Kemet C0603C475K8PAC

TDK C1608X5R1A475K

)

OUT

) of small, high-value,

EFF

GRM188R60J475K)

) outlined in Table 3.

EFF(MIN)

OUT

,

Table 3. Minimum C

Required for Stability

EFF

Operating Conditions

C

VIN (V) I

LOAD

(mA)

EFF(MIN)

2.3 to 4.5 0 to 200 1.5

2.7 to 4.5 0 to 200 1.0

2.3 to 4.5 0 to 150 1.0

C

varies with manufacturer, dielectric material, case size,

EFF

and temperature. Some manufacturers may be able to provide an X5R capacitor in 0402 case size that retains C >1.5μF with 5V bias; others may not. If this C

EFF

economically obtained and 0402 case size is required, the IC can work with the 0402 capacitor as long as the minimum V is restricted to >2.7V.

For best performance, a 10V-rated 0603 output capacitor is recommended (Kemet C0603C475K8PAC, or equivalent). Since it retains greater C

under bias and over

EFF

temperature, ouptut ripple can is reduced and transient capability enhanced.

(μF)

EFF

cannot be

IN

Output Voltage Ripple

Output voltage ripple is inversely proportional to C During t supplied by C

and

Therefore:

, when the boost switch is on, all load current is

ON

.

OUT

I

LOAD

tV •=

ON)PP(RIPPLE

−

SWSWON

−

SW)PP(RIPPLE

C

OUT

⎛

V

IN

⎜

−•=•=

1tDtt

⎜

V

OUT

⎝

⎛

V

IN

⎜

1tV •

−•=

⎜

V

OUT

⎝

⎞ ⎟ ⎟ ⎠

⎞

I

LOAD

⎟ ⎟ ⎠

C

OUT

where:

1

t =

SW

f

SW

As can be seen from Equation 4, the maximum V occurs when V

is minimum and I

IN

is maximum.

LOAD

OUT

(2)

(3)

(4)

(5)

RIPPLE

.

Startup

Input current limiting is in effect during soft-start, which limits the current available to charge C achieve regulation within the time period described in the soft-start section above; a FAULT occurs, causing the circuit to shut down, then restart after a significant time period. If

is a very high value, the circuit may not start on the first

C

OUT

attempt, but eventually achieves regulation if no load is present. If a high-current load and high capacitance are both present during soft-start, the circuit may fail to achieve

. If the output fails to

OUT

regulation and continually attempt soft-start, only to have

discharged by the load when in the FAULT state.

C

OUT

The circuit can start with higher values of C

under full

OUT

load if VIN is higher, since:

⎛

II •

⎜ ⎝

I

−=

)PK(LIMOUT

2

V

⎞

INRIPPLE

V

OUT

(

6)

⎟ ⎠

Generally, the limitation occurs in BST mode.

The FAN4860 starts on the first pass (without triggering a FAULT) under the following conditions for C

Table 4. Maximum C

for First-Pass Startup

EFF

EFF(MAX)

:

Operating Conditions

VIN (V)

5.0 V

R

LOAD(MIN)

3.3 V

OUT

C

EFF(MAX)

> 2.3 25Ω 16Ω 10

> 2.7 25Ω 16Ω 15

> 2.7 33Ω 20Ω 22

C

values shown in Table 4 typically apply to the lowest

EFF

. The presence of higher VIN enhances ability to start into

V

IN

larger C

at full load.

EFF

(μF)

C

may be necessary to preserve load transient response

OUT2

when the Schottky is used. When a load is applied at the FB pin, the forward voltage of the D1 rapidly increases before the regulator can respond or the inductor current can change. This causes an immediate drop of up to 300mV, depending on D1’s characteristics if C

is absent. C

OUT2

supplies instantaneous current to the load while the regulator adjusts the inductor current. A value of at least half of the minimum value of C

should be used for C

OUT

OUT2

. C needs to withstand the maximum voltage at the FB pin as the TVS is clamping.

The maximum DC output current available is reduced with this circuit, due to the additional dissipation of D1.

Layout Guideline

OUT2

FAN4860 — 3MHz, Synchronous TinyBoost™ Regulator

Transient Protection

To protect against external voltage transients caused by ESD discharge events, or improper external connections, some applications employ an external transient voltage suppressor (TVS) and Schottky diode (D1 in Figure 41).

Figure 41. FAN4860 with External Transient

Protection

The TVS is designed to clamp the FB line (system V +10V or –2V during external transient events. The Schottky diode protects the output devices from the positive excursion. The FB pin can tolerate up to 14V of positive excursion, while both the FB and VOUT pins can tolerate negative voltages.

The FAN4860 includes a circuit to detect a missing or defective D1 by comparing V

to FB. If V

OUT

– FB > about

OUT

0.7V, the IC shuts down. The IC remains shut down until < UVLO and VIN < UVLO+0.7 or EN is toggled.

V

OUT

) to

Figure 42. WLCSP Suggested Layout (Top View)

Figure 43. UMLP Suggested Layout (Top View)

Physical Dimensions

FAN4860 — 3MHz, Synchronous TinyBoost™ Regulator

2X

BALL A1

INDEX AREA

0.05 C

C

0.03

F

C

E

TOP VIEW

0.40

2

1

BOTTOM VIEW

A

B

D

F

0.03

C

2X

A1

0.40

RECOMMENDED LAND PATTERN

(NSMD PAD TYPE)

0.06 C

0.625 E

0.547

SEATING PLANE

D

0.378±0.018

SIDE VIEWS

Ø0.260±0.010

6X

C

(Y) +/-0.018

B

A

(X) +/-0.018

0.005 CAB

F

NOTES:

A. NO JEDEC REGISTRATION APPLIES.

B. DIMENSIONS ARE IN MILLIMETERS.

C. DIMENSIONS AND TOLERANCES PER ASMEY14.5M, 1994.

D. DATUM C, THE SEATING PLANE IS DEFINED BY THE SPHERICAL CROWNS OF THE BALLS.

E. PACKAGE TYPICAL HEIGHT IS 586 MICRONS ±39 MICRONS (547-625 MICRONS).

F. FOR DIMENSIONS D, E, X, AND Y SEE PRODUCT DATASHEET.

G. DRAWING FILENAME: UC006ACrev4.

Figure 44. 6-Lead, 0.4mm Pitch, WLCSP Package

0.40

(Ø0.20) Cu Pad

(Ø0.30) Solder Mask Opening

0.208±0.021

Product-Specific Dimensions

Product D E X Y

FAN4860UC5X

FAN4860UC33X

Package drawings are provided as a service to customers considering Fairchild components. Drawings may change in any manner without notice. Please note the revision and/or date on the drawing and contact a Fairchild Semiconductor representative to verify or obtain the most recent revision. Package specifications do not expand the terms of Fairchild’s worldwide terms and conditions, specifically the warranty therein, which covers Fairchild products.

Always visit Fairchild Semiconductor’s online packaging area for the most recent package drawings:

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

1.0 15

1.230mm +/-0.030mm 0.880mm +/-0.030mm 0.240mm 0.215mm

.

Physical Dimensions

FAN4860 — 3MHz, Synchronous TinyBoost™ Regulator

2X

IDENT

0.10 C

0.08

0.10 C

PIN1

C

0.05

0.00

SEATING

PLANE

2.0

TOP VIEW

0.55 MAX

SIDE VIEW

A

B

1.45

2.0

0.10

C

(0.25)

0.80

1.80

2X

0.50

6X

0.35

6X

A

(0.15)

RECOMMENDED LAND PATTERN

C

0.65

NOTES:

A. PACKAGE CONFORMS TO JEDEC MO-229 EXCEPT WHERE NOTED.

B. DIMENSIONS ARE IN MILLIMETERS.

C. DIMENSIONS AND TOLERANCES PER ASME Y14.5M, 1994.

D. LANDPATTERN RECOMMENDATION IS BASED

ON FSC DESIGN ONLY.

E. DRAWING FILENAME: MKT-UMLP06Erev2.

0.10 C A B

0.05 C

PIN1

IDENT

0.35

6X

0.25

6X

0.35

0.25

1.35

1.45

1

6

3

0.70

0.80

4

0.65

BOTTOM VIEW

Figure 45. 6-Lead UMLP Package

Package drawings are provided as a service to customers considering Fairchild components. Draw i ngs may change i n any manner wit hout notice. Please note the revision and/or date on the drawing and contact a Fairchild Semiconductor representative to verify or obtain the most recent revision. Package specifications do not expand the terms of Fairchild’s worldwide terms and conditions, specifically the warranty therein, which covers Fairchild products.

Always visit Fairchild Semiconductor’s online packaging area for the most recent package drawings:

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

.

1.0 16

FAN4860 — 3MHz, Synchronous TinyBoost™ Regulator

1.0 17