AME, Inc.
1
AME5107
Rev.A.01
PWM Control 3A Buck
Converter
C
l Input voltage: 3.6V to 18V.
l Output voltage: 0.8V to VCC.
l Duty ratio: 0% to 100% PWM control
l Oscillation frequency: 350KHz typ.
l Soft-start, Current limit, Enable function
l Thermal Shutdown function
l Built-in internal SW P-channel MOS
l SOP-8 Package
l All AME’s Lead Free Products Meet RoHS
Standards
AME5107provides low-ripple power, high efficiency, and
excellent transient characteristics. The PWM control cir-
cuit is able to vary the duty ratio linearly from 0 up to
100%. This converter also contains an error amplifier cir-
cuit as well as a soft-start circuit that prevents overshoot
at startup. An enable function, an over current protect func-
tion and a short circuit protect function are built inside,
and when OCP or SCP happens, the operation frequency
will be reduced from 350KHz to 30KHz. Also, an internal
compensation block is built in to minimum external com-
ponent count.
With the addition of an internal P-channel Power MOS,
a coil, capacitors, and a diode connected externally, these
ICs can function as step-down switching regulators. They
serve as ideal power supply units for portable devices when
coupled with the SOP-8L mini-package, providing such
outstanding features as low current consumption. Since
this converter can accommodate an input voltage up to
18V, it is also suitable for the operation via an AC adapter.
n General Description
n Features
n Applications
S
l PC Motherboard
l LCD Monitor
l Graphic Card
l DVD-Video Player
l Telecom Equipment
l ADSL Modem
l Printer and other Peripheral Equipment
l Microprocessor core supply
l Networking power supply
AME, Inc.
2
AME5107
Rev.A.01
PWM Control 3A Buck
Converter
n Typical Application
n Function Block Diagram
Note: VOUT = VFB x (1+RA/RB)
RB=0.7K~ 5K Ω
VOUT 2.5V 3.3V 5V
L1 Value 22uH 27uH 33uH
VIN=12V,IMAX=3A
SW
IN
GND
FB
100µA
VEN
Thermal
Shutdown
Oscillation
Circuit Reference Voltage
Source with Soft Start
+
-
PWM-Switched
Control Circuit
OCSET
EN
AME, Inc.
3
AME5107
Rev.A.01
PWM Control 3A Buck
Converter
C
n Pin Configuration
SOP-8
Top View
AME5107
1. FB
2. EN
3. OCSET
4. IN
5. SW
6. SW
7. GND
8. GND
* Die Attach:
Conductive Epoxy
n Pin Description
Pin Number Pin Name Pin Description
1FB
Output voltage Feedback input.
Set the output voltage by selecting values for Ra and Rb using:
Connect the ground of the feedback network to an AGND (Analog
Ground) plane which should be tied directly to the GND pin.
2EN
Enable Control Input, active high.
The enable pin is an active high control. Tie this pin above 2V to enable
the device. Tie this pin below 0.8V to shut down the device. In shutdown,
all function are disabled. Do not leave EN pin floating.
3OCSET Add an external resistor to set max output current.
4IN Input Supply Voltage Pin.
Bypass this pin with a capacitor. The capacitor shall be placed as close
to the device as possible.
5,6 SW Switch Node Connection to Inductor.
7,8 GND Ground.
Tie directly to ground plane.
+
=Rb
RbRa
VVOUT 8.0
1 32 4
AME5107
5678
AME, Inc.
4
AME5107
Rev.A.01
PWM Control 3A Buck
Converter
n Ordering Information
Operating Ambient Temperature Range
Number of Pins
Package Type
Pin Configuration
Special Feature
AME5107 x x x x xxx x
Output Voltage
n Ordering Information
A
1. FB
I:
-20
O
C to 85
O
C
H:
SOP
A:
8
ADJ:
Adjustable
Z:
Lead free
(SOP-8)
2. EN
3. OCSET
4. IN
5. SW
6. SW
7. GND
8. GND
Output Voltage Special Feature
Pin
Configuration Operating Ambient
Temperature Range Package Type Number
of
Pins
Note: ww represents the date code.
* A line on top of the first letter represents lead free plating such as 5107 AADJ yyww.
Please consult AME sales office or authorized Rep./Distributor for the availability of package type.
Part Number Marking* Output Voltage Package Operating Ambient
Temperature Range
AME5107AIHAADJZ 5107
AADJ
yyww ADJ SOP-8 -20OC to 85OC
AME, Inc.
5
AME5107
Rev.A.01
PWM Control 3A Buck
Converter
C
n Absolute Maximum Ratings
n Recommended Operating Conditions
Caution: Stree above the listed absolute maximum rating may cause permanent damage to the device.
*HBM B: 2000~3999V
n Thermal Information
* Measure θJC on center of molding compound if IC has no tab.
** MIL-STD-202G-210F
Parameter Package Die Attach Symbol Maximum Unit
Thermal Resistance*
(Junction to Case) SOP-8 θJC 60
Thermal Resistance
(Junction to Ambient) SOP-8 θJA 150
Internal Power Dissipation SOP-8 PD810 mW
350 oC
Solder Iron (10 Sec)**
Conductive Epoxy
oC / W
Parameter Symbol Maximum Unit
Input Supply Voltage IN -0.3V to 22V
EN,SW Pin Voltages VEN, VSW -0.3V to 0.3V
FB Pin Voltage VFB -0.3V to VIN
ESD Classification
V
TBD*
Parameter Symbol Rating Unit
Ambient Temperature Range TA-20 to 85 oC
Junction Temperature Range TJ-20 to 125 oC
Storage Temperature Range TSTG -40 to 150 oC
AME, Inc.
6
AME5107
Rev.A.01
PWM Control 3A Buck
Converter
n Electrical Specifications
VIN = 12V, TA = 25oC,Unless otherwise specified.
Parameter Symbol Min Typ Max Units
Input Voltage VIN 3.6 18 V
Feedback Voltage VFB 0.782 0.8 0.818 V
FB Pin Bias Current IFB 0.1 0.5 µA
Switch Current ISW 3.5 A
Current Consumption During
Power Off ISSS 10 µA
Output Voltage Line Regulation REGLINE 2 4 %
Output Voltage Load Regulation REGLOAD 0.2 0.5 %
Oscillator Frequency fOSC 300 350 400 KHz
Frequency of Current Limit or
Short Circuit Protect fOSC1 10 KHz
Enable High (enabled) VIH_EN 2.0
Enable Low (shutdown) VIL_EN 0.8
EN High Input Current IIH_EN 20 µA
EN Low Input Current IIL_EN -10 µA
OCSET Pin Bias Current IOCSET 75 90 105 µA
Soft Start Time tSS 0.3 2 5 mS
VIN=5V 110 150
VIN=12V 70 100
Internal MOSFET RDSON RDSON VFB=0V mΩ
Test Condition
VEN=0V
IOUT=0.1A
IOUT=0.1A
Measure wave form at SW
pin
VIN=5V to 18V
IOUT=0.1A to 3A
Measure wave form at SW
pin
V
Evaluate oscillation at SW
pin
Evaluate oscillation stop at
SW pin
AME, Inc.
7
AME5107
Rev.A.01
PWM Control 3A Buck
Converter
C
n Detailed Description
PWM Control
The AME5107 consists of DC/DC converters that employ a pulse-width modulation (PWM) system. In converters of
the AME5107, the pulse width varies in a range from 0 to 100%, according to the load current. The ripple voltage
produced by the switching can easily be removed through a filter because the switching frequency remains constant.
Therefore, these converters provide a low-ripple power over broad ranges of input voltage and load current.
Under Voltage Lockout
The under voltage lockout circuit of the AME5107 assures that the high-side MOSFET driver outputs remain in the off
state whenever the supply voltage drops below 3.3V. Normal operation resumes once VCC rises above 3.5V.
RDS(ON) Current Limiting
The current limit threshold is setting by the external resistor connecting from VCC supply to OCSET. The internal
100uA sink current crossing the resistor sets the voltage at the pin of OCSET. When the PWM voltage is less than the
voltage at OCSET, an over-current condition is triggered.
ILOAD x RDS(ON) =IOCSET x ROCSET
See above formula for setting the current limit value.
AME, Inc.
8
AME5107
Rev.A.01
PWM Control 3A Buck
Converter
n Characterization Curve(For reference only)
Vin vs. FB Line Regulation
0.74
0.75
0.76
0.77
0.78
0.79
0.80
0.81
0.82
0.83
0.84
0 2 4 6 8 10 12 14 16 18
VIN(V)
VFB(V)
IOUT =0.2A
VOUT=3.3V
VIN=12V
VIN (V)
3.10
3.15
3.20
3.25
3.30
3.35
3.40
0 2 4 6 8 10 12 14 16 18
VOUT(V)
IOUT=0.2A
VOUT=3.3V
Load Regulation VIN v.s Frequency
4.1
4.2
4.3
4.4
4.5
4.6
4.7
4.8
4.9
5.0
5.1
0 0.5 1 1.5 2 2.5 3
IOUT ( A )
VOUT ( V )
VIN=12V
340
345
350
355
360
365
370
375
380
0 2 4 6 8 10 12 14 16 18
VIN (V)
Fosc (KHZ)
IOUT=0.2A
VOUT=3.3V
Efficiency Vout Ripple
10
20
30
40
50
60
70
80
90
100
0 0.5 1 1.5 2 2.5 3
IOUT ( A )
Efficiency (% )
VOUT=5V
VOUT=3.3V
IOUT=0.1A
VOUT=3.3V
VIN=12V
20 mV/div
5V/div
VOUT
VSW
AME, Inc.
9
AME5107
Rev.A.01
PWM Control 3A Buck
Converter
C
n Characterization Curve(For reference only)
Vout Ripple Frequency of short current protect
Soft start time
5V/div
VSW
IOUT=3A
VOUT=3.3V
VIN=12V
20mV/div
5V/div
VOUT
VSW
2V/div
5V/div
5V/div
VOUT
VSW
EN
VIN =12V
VOUT=5V
ILOAD=3A
AME, Inc.
10
AME5107
Rev.A.01
PWM Control 3A Buck
Converter
n Tape and Reel Dimension
PIN 1W
P
AME
AME
Package Carrier Width (W) Pitch (P) Part Per Full Reel Reel Size
SOP-8 12.0±0.1 mm 4.0±0.1 mm 2500pcs 330±1 mm
Carrier Tape, Number of Components Per Reel and Reel Size
SOP-8
AME, Inc.
11
AME5107
Rev.A.01
PWM Control 3A Buck
Converter
C
n Package Dimension
SOP-8
MIN MAX MIN MAX
A1.35 1.75 0.05315 0.0689
A10.10 0.30 0.00394 0.01181
A2
B0.33 0.51 0.01299 0.02008
C0.19 0.25 0.00748 0.00984
D4.80 5.33 0.18898 0.20984
E3.80 4.00 0.14961 0.15748
e
L0.40 1.27 0.01575 0.05000
H5.80 6.30 0.22835 0.24803
y-0.10 -0.00394
θ0o8o0o8o
SYMBOLS MILLIMETERS INCHES
1.473 REF 0.05799 REF
1.27 BSC 0.05000 BSC
7o(4X)
Top View Side View
Front View
D
E
A
A2A1
e
B
H
θ
L
C
Life Support Policy:
These products of AME, Inc. are not authorized for use as critical components in life-support
devices or systems, without the express written approval of the president
of AME, Inc.
AME, Inc. reserves the right to make changes in the circuitry and specifications of its devices and
advises its customers to obtain the latest version of relevant information.
AME, Inc. , December 2007
Document: ORT6513-DS5107-A.01
Corporate Headquarter U.S.A. (Subsidiary)
AME, Inc. Analog Microelectronics, Inc.
2F, 302 Rui-Guang Road, Nei-Hu District 3100 De La Cruz Blvd., Suite 201
Taipei 114, Taiwan. Santa Clara, CA. 95054-2438
Tel: 886 2 2627-8687 Tel : (408) 988-2388
Fax: 886 2 2659-2989 Fax: (408) 988-2489
www.ame.com.tw
E-Mail: sales@ame.com.tw
