ETC AMC3100

AMC3100
1.5MHz, 600mA SYNCHRONOUS
STEP-DOWN CONVERTER
DESCRIPTION
FEATURES
The AMC3100 is a high efficiency synchronous buck
DC/DC converter using a constant frequency, current mode
architecture. Adjustable version and fixed output voltages of
1.2V, 1.5V and 1.8V are available. 300uA low supply current
at no load and <1µA supply current at shutdown. The 2.5V to
5.5V input voltage range makes the AMC3100 ideally suited
for single Li-Ion battery-powered applications. 100% duty
cycle provides low dropout operation, extending battery life in
portable systems. PWM pulse skipping mode operation
provides very low output ripple voltage for noise sensitive
applications.
Switching frequency is internally set at 1.5MHz,
allowing using small surface mount inductors and capacitors.
The internal synchronous switch increases efficiency and
eliminates the need for an external Schottky diode. Low
output voltages are easily supported with the 0.6V feedback
reference voltage.
The AMC3100 is available in a low profile (1mm) Thin
SOT-23-5L package.
TYPICAL APPLICATION
SW
RUN
4.7uF
„
„
„
„
„
„
„
„
„
GND
High Efficiency: Up to 96%
600mA Output Current at VIN=3V
2.5V to 5.5V Input Voltage Range
1.5MHz Constant Switching Frequency
No Schottky Diode Required
100% Duty Cycle as Low Dropout Operation
0.6V Reference Voltage Allows 0.6V
Minimum Output Voltage
<1µA Shutdown Mode Supply Current
Current Mode Operation for Excellent Line
and Load Transient Response
Over-temperature Protected
4KV HBM ESD Protection
5-Pin Thin SOT-23 package
APPLICATIONS
„
PDA, Personal Media Player
„
Smart Phone
Digital Still Camera, Video Camcorder
Portable Instruments
Bluetooth Headset
„
VOUT
AMC3100-1.8
CIN
„
„
L
VIN
„
„
VOUT ＝1.8V / 600mA
VIN＝2.5V to 5.5V
„
PACKAGE PIN OUT
COUT
10uF
GND 2
SW
SYMBOLIZATION
Device Name
Output Voltage
AMC3100DBFT
AMC3100-1.2DBFT
AMC3100-1.5DBFT
AMC3100-1.8DBFT
DB
Note:
Adjustable
1.2V Fixed
1.5V Fixed
1.8V Fixed
Marking
3
A64X
RUN 1
5
VFB / VOUT*
4 VIN
TSOT-23-5L
( Top View )
A64A
A642
A645
A648
* Note: VFB pin for adjustable version.
VOUT pin for fixed voltage version.
ORDER INFORMATION
SOT-23
5-pin
AMC3100DBF
(Adjustable)
AMC3100-X.XDBF (Fixed Voltage)
1. All surface-mount packages are available in Tape & Reel. Append the letter “T” to part number (i.e. AMC3100-1.8DBFT).
2. The letter ”F” is marked for Lead Free process.
Copyright © 2006 ADDtek Corp.
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-- JUNE 2006
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AMC3100
PIN DESCRIPTION
Pin Number
Pin Name
1
RUN
Enable pin. Higher than 1.5V to turn on the device. Lower than 0.3V to turn it off.
The shutdown mode supply current less than <1µA supply current. This pin should
not be floating.
2
GND
Ground
3
SW
Power Switch Output. Connects to the drains of the internal P-CH and N-CH
MOSFET switches.
4
VIN
Supply Input Pin.
5
VFB/VOUT
Pin Function
VFB (AMC3100): Feedback Input Pin. Connect VFB to the center point of the
external resistor divider. The feedback threshold voltage is 0.6V.
VOUT (AMC3100-X.X): Output Voltage Feedback Pin. An internal resistive divider
divides the output voltage down for comparison to the internal reference voltage.
PACKAGE THERMAL DATA
Thermal Resistance from Junction to Ambient, θJA
250 OC /W
Note :
Junction Temperature Calculation: TJ = TA + (PD x θJA).
PD: Power Dissipation, TA: Ambient temperature, θJA: Thermal Resistance-Junction to Ambient
The θJA numbers are guidelines for the thermal performance of the device/PC-board system.
All of the above assume no ambient airflow.
Copyright © 2006 ADDtek Corp.
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AMC3100
BLOCK DIAGRAM
SLOPE
C OM P
OSC
_
FR EQ
SH IFT
V F B /V O UT
5
R1
0.65V
OSC
_
+
0.6V
FB
0.4V
+
－
EA
SLEEP
+
BR UST
S
R2
Q
R
Q
RS LATC H
SW IT CH IN G
LOG IC
AN D
BLANK IN G
C IR C UIT
_
+
I CO M P
4
VIN
3
SW
2
GN D
5Ω
ANT ISH OOTT H RU
Bandgap
R eference
R UN
+
I RCM P
1
_
ABSOLUTE MAXIMUM RATINGS
(Note 1)
-0.3V to 6V
-0.3V to VIN
-0.3 to VIN+0.3V
800mA
800mA
1.3A
-40OC to 85OC
125OC
-60OC to 150OC
300OC
Input Voltage, VIN
RUN, VFB Voltage
SW Voltage
P-Channel Switch Source Current (DC)
N-Channel Switch Sink Current (DC)
Peak SW Sink and Source Current
Operating Temperature Range (Note 2)
Junction Temperature, TJ (Note 3)
Storage Temperature Range
Lead Temperature (soldering, 10 seconds)
Note 1: Absolute Maximum Ratings are those values beyond which the life of a device may be impaired.
Note 2: The AMC3100 is guaranteed to meet performance specifications from 0°C to 70°C. Specifications over the –40°C to 85°C operating
temperature range are assured by design, characterization and correlation with statistical process controls.
Note 3: TJ is calculated from the ambient temperature TA and power dissipation PD according to the following formula:
TJ = TA + (PD x θJA).
Copyright © 2006 ADDtek Corp.
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AMC3100
RECOMMENDED OPERATING CONDITIONS
Parameter
Symbol
Min
Supply Voltage
VIN
Operating free-air temperature range
TA
Typ
Max
Unit
2.5
5.5
V
-40
85
℃
ELECTRICAL CHARACTERISTICS
VIN=3.6V, TA=25°C. (Unless otherwise noted)
Parameter
Symbol
Input DC Supply Current
Active Mode
IS
Shutdown
Regulated Output Voltage
VOUT
Output Voltage Line Regulation
△VOUT
Output Voltage Load Regulation
VLDREG
Peak Inductor Current
IPK
Feedback Current
IVFB
Regulated Feedback Voltage
Reference Voltage Line Regulation
VFB
△VFB
Condition
Typ
Max
VFB=0.5V or VOUT=90%,
ILOAD=0A
300
400
VRUN=0V, VIN=4.2V
0.1
1
1.800
1.500
1.200
1.854
1.545
1.236
0.04
0.4
AMC3100-1.8, IOUT=100mA
AMC3100-1.5, IOUT=100mA
AMC3100-1.2, IOUT=100mA
Min
µA
1.746
1.455
1.164
VIN=2.5V to 5.5V
0.5
Duty Cycle < 35%, VIN=3V,
VFB=0.5V or VOUT=90%,
TA= 25°C
TA= 0°C ≤ TA ≤ 85°C
TA= -40°C ≤ TA ≤ 85°C
Unit
0.75
0.5880
0.5865
0.5850
VIN=2.5V to 5.5V
%V
%
1.25
A
±30
nA
0.6
0.6
0.6
0.6120
0.6135
0.6150
V
0.04
0.4
%V
1.5
1.8
MHz
Oscillator Frequency
fOSC
VFB=0.6V or VOUT=100%
RDS(ON) of P-Channel FET
RPFET
ISW=100mA
0.4
0.5
Ω
RDS(ON) of N-Channel FET
RNFET
ISW=-100mA
0.35
0.45
Ω
SW Leakage
ILSW
VRUN=0V, VSW=0V or 5V,
VIN=5V
±0.01
±1
µA
RUN Threshold
VRUN
1
1.5
V
RUN Leakage Current
IRUN
±0.01
±1
µA
Copyright © 2006 ADDtek Corp.
1.2
1
V
0.3
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AMC3100
CHARACTERIZATION CURVES
Efficiency vs Output Current
Efficiency vs Output Current
100
VIN=2.7V
90
80
70
VIN=5.5V
50
VIN=5.5V
60
VIN=4.2V
50
VIN=4.2V
40
40
30
30
VOUT =1.5V
TA=25°C
20
10
10
10
Output Current ( mA )
30
10
Output Current ( mA )
0.1
1000
1.8
I LOAD=100mA
80
75
I LOAD=10mA
70 I LOAD=300mA
65
I LOAD=600mA
60
VOUT =2.5V
TA=25°C
55
50
2
3
4
5
1.6
1.5
1.4
1.3
I LOAD=200mA
1.2
I LOAD=100mA
1.1
-50 -25
Load Regulation
1.4
1.3
ILOAD=200 mA
25
50
2
75 100 125 150
3
4
5
6
Supply Voltage ( V )
RDS (ON) vs Tem perature
0.6
ILOAD=100 mA
0.5
R DS(ON) ( Ω )
1.51
0
0.6
VIN=3.6V
VOUT =1.5V
TA=25°C
1.52
I LOAD=100 mA
1.5
RDS (ON) vs Input Voltage
1.55
1.53
1.6
Temperature ( °C )
Input Voltage ( V )
1.54
VOUT =1.5V
TA=25°C
1.7
1.2
1
6
0.5
TA=25°C
0.4
R DS(ON) ( Ω )
85
1000
Oscillator Frequency vs
Supply Voltage
VIN=3.6V
VOUT =1.5V
1.7
10
Output Current ( mA )
Oscillator Frequency (MHz)
Oscillator Frequency (MHz)
90
VOUT=2.5V
TA=25°C
10
1.8
I LOAD=250mA
95
Efficiency ( % )
40
Oscillator Frequency vs
Tem perature
Efficiency vs Input Voltage
100
VIN=3.6V
50
0
0.1
1000
VIN=5.5V
60
0
0.1
Output Voltage ( V )
70
20
VOUT =1.8V
TA=25°C
20
0
VIN=4.2V
80
70
VIN=3.6V
60
VIN=2.7V
90
VIN=3.6V
Efficiency ( % )
Efficiency ( % )
VIN=2.7V
90
80
Efficiency vs Output Current
100
Efficiency ( % )
100
Main switch
0.3
0.2
0.1
0.4
VIN=3.6V
Main switch
VIN=4.2V
Synchronous
VIN=2.7V
0.3
0.2
switch
0.1
Synchronous switch
1.5
0
0
100 200 300 400 500 600 700 800
Output Current ( mA )
Copyright © 2006 ADDtek Corp.
0
2
3
4
5
Input Voltage ( V )
5
6
7
-50 -25
0 25 50 75 100 125 150
Temperature ( °C )
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AMC3100
Dynam ic Supply Current vs
Tem perature
Dynam ic Supply Current vs
Supply Voltage
380
340
320
300
280
260
240
220
10
360
VIN=3.6V
VOUT =1.5V
I LOAD=0mA
340
320
Switch Leakage Current (uA)
VOUT =1.5V
I LOAD=0mA
TA=25°C
360
Dynamic Supply Current ( uA )
Dynamic Supply Current( uA )
380
Sw itch Leakage vs
Tem perature
300
280
260
240
220
200
200
2
3
4
5
-50 -25
6
0
25
50
VRUN=0V
VIN=5V
8
6
v SW =5V
4
v SW=0V
2
0
75 100 125 150
-50 -25
Transient vs Output Current
Line Regulation
1.5
1.4
30
25
20
15
10
1.3
5
1.2
0
0
1
2
3
4
5
Input Voltage ( V )
0.66
0.64
0.62
0.6
0.58
0.56
0.54
0.52
0.5
0
6
VIN=3.6V
I LOAD=100mA
0.68
VOUT =1.5V
TA=25°C
Reference Voltage( V )
Transient Voltage ( mV )
Output Voltage ( V )
1.6
100 200 300 400 500 600 700 800
-50 -25
Output Current ( mA )
Discontinuous Operation
75 100 125 150
0.7
35
VOUT =1.5V
TA=25°C
50
Reference Voltage vs
Tem perature
40
1.8
25
Temperature ( °C )
Temperature ( °C )
Supply Voltage ( V )
1.7
0
0 25 50 75 100 125 150
Temperature (°C )
Load Step
Start-up from Shutdown
VOUT
SW
2V/DIV
VOUT
10mV/DIV
RUN
5V/DIV
100mV/DIV
VOUT
1V/DIV
IL
500mA/DIV
AC Coupled
IL
200mA/DIV
ILOAD
IL
500mA/DIV
500mA/DIV
40us/DIV
VIN =3.6V
20us/DIV
VOUT =1.5V
ILOAD=0mA to 600mA
Copyright © 2006 ADDtek Corp.
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AMC3100
Load Step
Load Step
Load Step
VOUT
V OUT
VOUT
100mV/DIV
100mV/DIV
100mV/DIV
IL
IL
IL
500mA/DIV
500mA/DIV
500mA/DIV
ILOAD
ILOAD
ILOAD
500mA/DIV
500mA/DIV
500mA/DIV
VIN =3.6V
20us/DIV
VOUT =1.5V
ILOAD=50mA to 600mA
Copyright © 2006 ADDtek Corp.
VIN =3.6V
20us/DIV
VOUT =1.5V
ILOAD=100mA to 600mA
7
VIN =3.6V
20us/DIV
VOUT =1.5V
ILOAD=200mA to 600mA
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AMC3100
APPLICATION INFORMATION
The basic AMC3100 application circuit is shown in Figure 1. External component selection is driven by load
requirement:
Adjustable Output Voltage:
In adjustable version, the output voltage is set by the below formula (1):
R1 ⎞
⎛
VOUT = 0 .6V ⎜1 +
⎟
R2 ⎠
⎝
0.6V≦VOUT≦5.5V
(1)
The external resistor divider sets the output voltage (see figure 1). Choose R1 around 1MΩ, R2 is then given by:
R1
R2 =
⎞
⎛ V OUT
− 1⎟
⎜
⎠
⎝ 0 . 6V
VOUT＝2.5V
VIN＝2.5V to 5.5V
Rectified
Table 1- Resistor Selection vs. Adjust Output Voltage.
L1
R1
2.2uH
1MΩ
VIN
SW
CIN
RUN
22pF
FB
AMC3100-ADJ
4.7uF
C1
GND
R2
316KΩ
COUT
10uF
VOUT
R1
1.2V
1MΩ, 1%
1MΩ, 1%
R2
1.5V
1MΩ, 1%
667KΩ, 1%
1.8V
1MΩ, 1%
500KΩ, 1%
2.5V
1MΩ, 1%
316KΩ, 1%
3.3V
1MΩ, 1%
222KΩ, 1%
Figure 1
Inductor selection:
For most applications, the value of the inductor will fall in the range of 1uH to 4.7uH. Its value is chosen
based on the desired ripple current. Large value inductors lower ripple current, and small value inductors result in
higher ripple currents.
Higher VIN or VOUT also increases the ripple current as shown in the formula (2):
∆I L =
VOUT
fL
⎛ VOUT
⎜⎜1 −
VIN
⎝
⎞
⎟⎟
⎠
Where, f = operating frequency, andΔIL = ripple current in the inductor.
(2)
COUT selection:
The output capacitor keeps output voltage ripple small and ensures regulation loop stable. The output capacitor
impedance shall be low in switching frequency. The output rippleΔVOUT approximately:
⎛
1
∆VOUT ≅ ∆I L ⎜⎜ ESR +
8 fCOUT
⎝
⎞
⎟⎟
⎠
Copyright © 2006 ADDtek Corp.
Where, COUT = output capacitance.
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AMC3100
PACKAGE
‧
TSOT-23-5L
Note: All dimensions in mm.
Copyright © 2006 ADDtek Corp.
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