Fairchild FAN2106 service manual

FAN2106 — TinyBuck™ 3-24V Input, 6A, High-Efficiency, Integrated Synchronous Buck Regulator

Features

 6A Output Current  Wide Input Range: 3V - 24V  Output Voltage Range: 0.8V to 80% V

IN

 Over 95% Peak Efficiency  1% Reference Accuracy Over Temperature  Programmable Frequency Operation: 200KHz to

600KHz

 Fully Synchronous Operation with Integrated

Schottky Diode on Low-Side MOSFET Boosts Efficiency

 Internal Bootstrap Diode  Internal Soft-Start  Power-Good Signal  Starts on Pre-Biased Outputs  Accepts Ceramic Capacitors on Output  External Compensation for Flexible Design  Programmable Current Limit  Under-Voltage, Over-Voltage, and Thermal

Protections

 5x6mm, 25-Pin, 3-Pad MLP Package

Applications



Servers & Telecom

 Graphics Cards & Displays  Computing Systems  Point-of-Load Regulation  Set-Top Boxes & Game Consoles

Description

The FAN2106 TinyBuck™ is a highly efficient, smallfootprint, constant-frequency, 6A, integrated synchronous buck regulator.

The FAN2106 contains both synchronous MOSFETs and a controller/driver with optimized interconnects in one package, which enables designers to solve highcurrent requirements in a small area with minimal external components. Integration helps to minimize critical inductances, making component layout simpler and more efficient compared to discrete solutions.

The FAN2106 provides for external loop compensation, programmable switching frequency, and current limit. These features allow design flexibility and optimization. High-frequency operation allows for all-ceramic solutions.

The summing current-mode modulator uses lossless current sensing for current feedback and over-current protection. Voltage feedforward helps operation over a wide input voltage range.

Fairchild’s advanced BiCMOS power process, combined with low-R thermally efficient MLP package, provide the ability to dissipate high power in a small package.

Output over-voltage, under-voltage, over-current, and thermal shutdown protections help protect the device from damage during fault conditions. FAN2106 prevents pre-biased output discharge during startup in point-of-load applications.

DS(ON)

Related Resources

 AN-8022 — TinyCalc™ Calculator User Guide  TinyCalc™ Calculator Design Tool

FAN2106 — TinyBuck™ 3-24V Input, 6A, High-Efficiency, Integrated Synchronous Buck Regulator

September 2011

internal MOSFETs and a

Ordering Information

Part Number

FAN2106MPX -10°C to 85°C Molded Leadless Package (MLP) 5x6mm Tape and Reel

FAN2106EMPX -40°C to 85°C Molded Leadless Package (MLP) 5x6mm Tape and Reel

Operating

Temperature Range

Package Packing Method

Typical Application Diagram

FAN2106 — TinyBuck™ 3-24V Input, 6A, High-Efficiency, Integrated Synchronous Buck Regulator

Block Diagram

Figure 1. Typical Application

Figure 2. Block Diagram

Pin Configuration

FAN2106 — TinyBuck™ 3-24V Input, 6A, High-Efficiency, Integrated Synchronous Buck Regulator

Figure 3. MLP 5x6mm Pin Configuration (Bottom View)

Pin Definitions

Pin # Name Description

P1, 6-12 SW

P2, 2-5 VIN

P3, 21-23 PGND

1 BOOT

13 PGOOD

14 EN

15 VCC

16 AGND

17 ILIM

18 R(T) 19 FB 20 COMP 24 NC 25 RAMP

Switching Node. Junction of high-side and low-side MOSFETs. Power Input Voltage. Connect to the main input power source. Power Ground. Power return and Q2 source. High-Side Drive BOOT Voltage. Connect through capacitor (C

an internal synchronous bootstrap diode to recharge the capacitor on this pin to VCC when SW is LOW.

Power-Good Flag. An open-drain output that pulls LOW when FB is outside the limits specified in electrical specs. PGOOD does not assert HIGH until the fault latch is enabled.

ENABLE. Enables operation when pulled to logic HIGH or left open. Toggling EN resets the regulator after a latched fault condition. This input has an internal pull-up when the IC is functioning normally. When a latched fault occurs, EN is discharged by a current sink.

Input Bias Supply for IC. The IC’s logic and analog circuitry are powered from this pin. This pin should be decoupled to AGND through a >1µF X5R/X7R capacitor.

Analog Ground. The signal ground for the IC. All internal control voltages are referred to this pin. Tie this pin to the ground island/plane through the lowest impedance connection.

Current Limit. A resistor (R limit trip threshold lower than the default setting.

Oscillator Frequency. A resistor (R frequency.

Output Voltage Feedback. Connect through a resistor divider to the output voltage. Compensation. Error amplifier output. Connect the external compensation network between

this pin and FB.

No Connect. This pin is not used. Ramp Amplitude. A resistor (R

and provides voltage feedforward functionality.

) to SW. The IC includes

BOOT

) from this pin to AGND can be used to program the current-

ILIM

) from this pin to AGND sets the PWM switching

T

) connected from this pin to VIN sets the ramp amplitude

RAMP

FAN2106 — TinyBuck™ 3-24V Input, 6A, High-Efficiency, Integrated 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.

Parameter Conditions Min. Max. Unit

VIN to PGND 28 V

VCC to AGND AGND = PGND 6 V

BOOT to PGND 35 V

BOOT to SW -0.3 6.0 V

SW to PGND

All other pins -0.3 VCC+0.3 V

ESD

Continuous -0.5 24.0 Transient (t < 20ns, f < 600KHz) -5.0 30.0

Human Body Model, JEDEC JESD22-A114 2.0 Charged Device Model, JEDEC JESD22-C101 2.5

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 Conditions Min. Typ. Max. Unit

VCC Bias Voltage VCC to AGND 4.5 5.0 5.5 V

VIN Supply Voltage VIN to PGND 3 24 V

TA Ambient Temperature

FAN2106MPX -10 +85 FAN2106EMPX -40 +85

°C

TJ Junction Temperature +125 °C

fSW Switching Frequency 200 600 KHz

Thermal Information

Symbol Parameter Min. Typ. Max. Unit

T

Storage Temperature -65 +150 °C

STG

TL Lead Soldering Temperature, 10 Seconds +300 °C

P1 (Q2) 4

Thermal Resistance: Junction-to-Case

Thermal Resistance: Junction-to-Mounting Surface 35



JC

J-PCB

PD Power Dissipation, TA = 25°C 2.8

Note:

1. Typical thermal resistance when mounted on a four-layer, two-ounce PCB, as shown in Figure 26. Actual results are dependent on mounting method and surface related to the design.

P2 (Q1) 7 P3 4

(1)

°C/W

(1)

W

°C/W

Electrical Specifications

Electrical specifications are the result of using the circuit shown in Figure 1 with VIN = 12V, unless otherwise noted.

Parameter Conditions Min. Typ. Max. Unit

Power Supplies

SW = Open, FB = 0.7V, VCC = 5V, f

= 600KHz

VCC Current

SW

Shutdown: EN = 0, VCC = 5V 7 10 µA

VCC UVLO Threshold

Rising VCC 4.1 4.3 4.5 V Hysteresis 300 mV

Oscillator

Frequency

RT = 50K RT = 24K

Minimum On-Time Ramp Amplitude, Peak-to-Peak Minimum Off-Time

(2)

50 65 ns

, 1.8V

16V

IN

= 200K

R

(2)

100 150 ns

RAMP

, RT = 30K,

OUT

Reference

Reference Voltage (VFB)

(3)

FAN2106MPX, TA = 25°C 794 800 806 mV FAN2106EMPX, TA = 25°C 795 800 805 mV

Error Amplifier

DC Gain Gain Bandwidth Product Output Voltage (V Output Current, Sourcing V Output Current, Sinking V

(2)

12 15 MHz

) 0.4 3.2 V

COMP

V

= 5V

CC

= 5V, V

CC

= 5V, V

CC

= 2.2V 1.5 2.2 mA

COMP

= 1.2V 0.8 1.2 mA

COMP

FB Bias Current VFB = 0.8V, TA = 25°C -850 -650 -450 nA

Protection and Shutdown

Open, fSW = 500KHz, V

R

Current Limit I

Current VCC = 5V, TA = 25°C -11 -10 -9 µA

LIM

Over-Temperature Shutdown Over-Temperature Hysteresis +30 °C

ILIM

= 200K16 Consecutive Cycles

R

RAMP

Internal IC Temperature

= 1.8V,

OUT

Over-Voltage Threshold 2 Consecutive Clock Cycles 110 115 120 %V Under-Voltage Shutdown 16 Consecutive Clock Cycles 68 73 78 %V Fault Discharge Threshold Measured at FB Pin 250 mV Fault Discharge Hysteresis Measured at FB Pin (VFB ~500mV) 250 mV

Soft-Start

V

to Regulation (T0.8)

OUT

Fault Enable/SSOK (T1.0) 6.7 ms

Frequency = 600KHz

8 12 mA

255 300 345 KHz 540 600 660 KHz

0.53 V

80 85 dB

6 8 10 A

+155 °C

OUT

5.3 ms

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FAN2106 — TinyBuck™ 3-24V Input, 6A, High-Efficiency, Integrated Synchronous Buck Regulator

Fairchild FAN2106 service manual

Specifications and Main Features

Frequently Asked Questions

User Manual