FAN2106 — TinyBuck™ 3-24V Input, 6A, High-Efficiency, Integrated Synchronous Buck Regulator
November 2012
FAN2106 — TinyBuck™
3-24 V Input, 6 A, High-Efficiency,
Integrated Synchronous Buck Regulator
Features
6 A Output Current
Wide Input Range: 3 V - 24 V
Output Voltage Range: 0.8 V to 80% V
IN
Over 95% Peak Efficiency
1% Reference Accuracy Over Temperature
Programmable Frequency Operation: 200 KHz to
600 KHz
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
5x6 mm, 25-Pin, 3-Pad MLP Package
Description
The FAN2106 TinyBuck™ is a highly efficient, small-
footprint,
constant-frequency,
6 A,
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 high-
current 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
DS(ON)
internal MOSFETs and a
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.
Applications
Servers & Telecom
Graphics Cards & Displays
Computing Systems
Point-of-Load Regulation
Set-Top Boxes & Game Consoles
Ordering Information
Part Number
FAN2106MPX
FAN2106EMPX
Related Resources
AN-8022 — TinyCalc™ Calculator User Guide
TinyCalc™ Calculator Design Tool
Operating
Temperature Range
-10°C to 85°C
-40°C to 85°C
Package
Molded Leadless Package (MLP) 5x6 mm
Molded Leadless Package (MLP) 5x6 mm
Packing Method
Tape and Reel
Tape and Reel
© 2009 Fairchild Semiconductor Corporation
FAN2106 • Rev. 1.1.2
www.fairchildsemi.com
FAN2106 — TinyBuck™ 3-24V Input, 6A, High-Efficiency, Integrated Synchronous Buck Regulator
Typical Application Diagram
Figure 1. Typical Application
Block Diagram
Figure 2. Block Diagram
© 2009 Fairchild Semiconductor Corporation
FAN2106 • Rev. 1.1.2
www.fairchildsemi.com
2
FAN2106 — TinyBuck™ 3-24V Input, 6A, High-Efficiency, Integrated Synchronous Buck Regulator
Pin Configuration
Figure 3. MLP 5x6 mm Pin Configuration (Bottom View)
Pin Definitions
Pin #
P1, 6-12
P2, 2-5
P3, 21-23
1
13
14
Name
SW
VIN
PGND
BOOT
PGOOD
EN
Description
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
BOOT
) to SW. The IC includes
an internal synchronous bootstrap diode to recharge the capacitor on this pin to V
CC
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 >1 µF 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
ILIM
) from this pin to AGND can be used to program the current-
limit trip threshold lower than the default setting.
Oscillator Frequency.
A resistor (R
T
) from this pin to AGND sets the PWM switching
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
RAMP
) connected from this pin to VIN sets the ramp amplitude
and provides voltage feedforward functionality.
15
16
17
18
19
20
24
25
VCC
AGND
ILIM
R(T)
FB
COMP
NC
RAMP
© 2009 Fairchild Semiconductor Corporation
FAN2106 • Rev. 1.1.2
www.fairchildsemi.com
3
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
VIN to PGND
VCC to AGND
BOOT to PGND
BOOT to SW
SW to PGND
All other pins
ESD
Continuous
AGND = PGND
Conditions
Min.
Max.
28
6
35
Unit
V
V
V
V
V
V
kV
-0.3
-0.5
-5.0
-0.3
Human Body Model, JEDEC JESD22-A114
Charged Device Model, JEDEC JESD22-C101
2.0
2.5
Transient (t < 20 ns, f < 600 KHz)
6.0
24.0
30.0
V
CC
+0.3
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
V
CC
V
IN
T
A
T
J
f
SW
Parameter
Bias Voltage
Supply Voltage
Ambient Temperature
Junction Temperature
Switching Frequency
Conditions
VCC to AGND
VIN to PGND
FAN2106MPX
FAN2106EMPX
Min.
4.5
3
-10
-40
200
Typ.
5.0
Max.
5.5
24
+85
+85
+125
600
Unit
V
V
°C
°C
KHz
Thermal Information
Symbol
T
STG
T
L
θ
JC
θ
J-PCB
P
D
Storage Temperature
Lead Soldering Temperature, 10 Seconds
P1 (Q2)
Thermal Resistance: Junction-to-Case
P2 (Q1)
P3
Thermal Resistance: Junction-to-Mounting Surface
Power Dissipation, T
A
= 25°C
4
7
4
35
(1)
2.8
(1)
°C/W
W
°C/W
Parameter
Min.
-65
Typ.
Max.
+150
+300
Unit
°C
°C
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.
© 2009 Fairchild Semiconductor Corporation
FAN2106 • Rev. 1.1.2
www.fairchildsemi.com
4
FAN2106 — TinyBuck™ 3-24V Input, 6A, High-Efficiency, Integrated Synchronous Buck Regulator
Electrical Specifications
Electrical specifications are the result of using the circuit shown in Figure 1 with V
IN
= 12 V, unless otherwise noted.
Parameter
Power Supplies
V
CC
Current
Conditions
SW = Open, FB = 0.7 V, V
CC
= 5 V,
f
SW
= 600 KHz
Shutdown: EN = 0, V
CC
= 5 V
Rising V
CC
Hysteresis
R
T
= 50 KΩ
R
T
= 24 KΩ
16 V
IN
, 1.8 V
OUT
, R
T
= 30 KΩ,
R
RAMP
= 200 KΩ
Min.
Typ.
Max.
Unit
8
7
4.1
4.3
300
255
540
300
600
50
0.53
100
12
10
4.5
mA
µA
V
mV
V
CC
UVLO Threshold
Oscillator
Frequency
Minimum On-Time
(2)
Ramp Amplitude, Peak-to-Peak
Minimum Off-Time
(2)
Reference
Reference Voltage (V
FB
)
(3)
Error Amplifier
DC Gain
(2)
Gain Bandwidth Product
(2)
Output Voltage (V
COMP
)
Output Current, Sourcing
Output Current, Sinking
FB Bias Current
Protection and Shutdown
Current Limit
I
LIM
Current
Over-Temperature Shutdown
Over-Temperature Hysteresis
Over-Voltage Threshold
Under-Voltage Shutdown
Fault Discharge Threshold
Fault Discharge Hysteresis
Soft-Start
V
OUT
to Regulation (T0.8)
Fault Enable/SSOK (T1.0)
345
660
65
KHz
KHz
ns
V
150
806
805
ns
mV
mV
dB
MHz
FAN2106MPX, T
A
= 25°C
FAN2106EMPX, T
A
= 25°C
794
795
80
800
800
85
15
V
CC
= 5 V
V
CC
= 5 V, V
COMP
= 2.2 V
V
CC
= 5 V, V
COMP
= 1.2 V
V
FB
= 0.8 V, T
A
= 25°C
R
ILIM
Open, f
SW
= 500 KHz, V
OUT
=
1.8 V, R
RAMP
= 200 KΩ, 16 Consecutive
Cycles
V
CC
= 5 V, T
A
= 25°C
Internal IC Temperature
2 Consecutive Clock Cycles
16 Consecutive Clock Cycles
Measured at FB Pin
Measured at FB Pin (V
FB
~500 mV)
12
0.4
1.5
0.8
-850
3.2
2.2
1.2
-650
-450
V
mA
mA
nA
6
-11
8
-10
+155
+30
10
-9
A
µA
°C
°C
110
68
115
73
250
250
5.3
6.7
120
78
%V
OUT
%V
OUT
mV
mV
ms
ms
Frequency = 600 KHz
Continued on the following page…
© 2009 Fairchild Semiconductor Corporation
FAN2106 • Rev. 1.1.2
www.fairchildsemi.com
5