AMS AMS3109

AMS3109
General Description
Features
•
•
•
•
•
•
•
•
The AMS3109 is a high performance linear regulator
with very low dropout voltage and excellent transient
response. It is designed to operate with wide input
voltage range of 1.5 – 12Volts making it ideal for two
step conversion while maintaining high efficiency for
many power sensitive applications. The device is
capable of supplying 700mA of output current with a
typical dropout voltage of 550mV. The product is
available in adjustable output voltage.
The linear regulator has been optimized for noise
sensitive applications.
The device includes an
Enable pin for electrical on/off of the regulator.
Forcing the Enable pin to logic low shuts down the
LDO and reduces the supply current below 1µA.
•
•
•
•
•
•
The product includes complete short-circuit and
thermal protection. The combination of these two
internal protection circuits gives the device a
comprehensive safety system to safe guard against
extreme adverse operating conditions.
•
The AMS3109 is available in a thermally enhanced
SOIC-8 EDP package, and it is rated for -40°C to
+125°C temperature range.
VIN range: 1.5 – 12V
Adjustable output voltage as low as 0.6V
700mA maximum output current
550mV typical dropout voltage at 700mA
Low self noise
Enable (EN) pin for LDO on/off
120µA typical supply current
ByPass (CBYP) Pin for low PSRR and output
noise
PSRR > 40dB at 10KHz
Stable with Electrolytic, Tantalum or
Ceramic capacitors
Current Limit protection
Over-Temperature Shutdown
-40 to +125°C temperature range
Thermally enhanced SOIC-8 exposed
paddle package
RoHS & WEEE compliant
Applications
•
•
•
•
•
•
•
•
ASIC Power Supplies In:
¾ Set-top Boxes, Desktops, Notebooks
¾ Graphic Cards, Printers and Copiers
DVD, Blue-Ray DVD writers
LCD TVs and LCD monitors
Infotainment
Wireless & RF: applications
DSP and FPGA Power Supplies
Medical Instrumentation
SMPS Post-Regulator
Typical Application
1
Advanced Monolithic Systems
http://www.ams-semitech.com
AMS3109
Pin Description (SOIC-8 EDP package)
Pin #
Symbol
Description
1
BYP
Reference Bypass pin. Connect an external capacitor from CBYP to ground to
bypass the noise generated by the internal bandgap. This improves power supply
rejection ratio and output noise.
2
NC
No Connection
3
GND
4
VIN
5
VOUT
Output Voltage
6
ADJ
Provides feedback to error amplifier from the resistive divider that sets the output
voltage.
7
NC
No Connection
8
EN
Enable pin. It controls the electrical on/off of the device. When connected to logic
low, the device shuts off and consumes less than1µA of current. Logic high will
resume normal operation.
9
GND
Ground
Input supply Voltage. It powers the internal control circuitry and the internal power
switch. Bypass VIN with at ceramic capacitor from this pin to ground.
Expose pad. Connected to PCB ground plane for good thermal dissipation.
Pin Configuration
SOIC-8EDP (Top View)
2
Advanced Monolithic Systems
http://www.ams-semitech.com
AMS3109
Absolute Maximum Ratings (1)
Recommended Operating Conditions (2)
Maximum Input Supply Voltage (VIN)………....……..… -0.3V to 15V
Enable Voltage (EN)……………..…..………….……… -0.3V to 15V
Adjustable Voltage (ADJ).……...………………………… -0.3V to 3V
ByPass Voltage (BYP)…………..…..…………………… -0.3V to 3V
Storage Temperature Range……………................. -65⁰C to 150⁰C
Lead Temperature…………………..…………...……………… 260⁰C
Junction Temperature………...………………..…..…………… 125⁰C
Input Voltage……………………………..……….……….. 1.5V to 12V
Ambient Operating Temperature…………….……… -40⁰C to 125⁰C
Thermal Information
8L SOIC EP θJA
(3)
……………………………….……….…...45⁰C/W
Electrical Characteristics
Unless otherwise noted: VIN=3.3V, VOUT=1.8V, CIN=10 µF, COUT=22µF, -40⁰C≤TA=TJ≤85⁰C, TJ(Max.)= 125°C, Typical values are TA= 25°C
Parameter
Symbol
Conditions
Min.
Output Voltage Accuracy
VOUT
-3
Adjustable Voltage
VADJ
0.588
Adjustable bias current
IADJ_Bias
Maximum Output Current
IOUT_Max
Typ.
Max.
Units
3
%
0.600
0.612
V
10
100
nA
700
mA
Load Regulation
IOUT= 0 – 700mA
0.6
%
Line Regulation
VIN=3.0 – 12V; IOUT=100mA
0.15
%
Supply Current
ISUP
VIN=3.3V, Io=0A
120
Shutdown Current
ISHDN
VIN=3.3V, VEN=0V
<1
µA
800
mA
Current Limit
ILIM
Dropout Voltage
IOUT=100mA; VOUT=95% of VOUT(NOM)
220
IOUT=250mA; VOUT=95% of VOUT(NOM)
300
IOUT=500mA; VOUT=95% of VOUT(NOM)
425
IOUT=750mA; VOUT=95% of VOUT(NOM)
600
F=10KHz Io=20mA
33
150
VDO
ΔVOUT/ΔVIN
PSRR
Output Noise Voltage
en
µA
mV
BW: 100Hz–100 KHz
COUT = 22µF
ILOAD = 150mA
No CBYP
dB
118
µV(rms)
CBYP = 10nF
33
Enable Threshold Low
VEN(L)
1
V
Enable Threshold High
VEN(H)
1.1
V
Input Enable Low Current
IEN(L)
VEN = 0V
Input Enable High Current
IEN(H)
VEN = 1.5V
Thermal Shutdown
TSD
145
°C
TSD_HYS
15
°C
Thermal Shutdown Hysteresis
Notes:
1.
2.
3.
0
10
nA
150
300
nA
Stresses above those listed in Absolute Maximum Ratings may cause permanent damage to the device.
Measured on approximately 1” square of 1 oz. copper.
The total power dissipation for SO-8 EDP package is recommended to 2.5W rated at 25⁰C ambient temperature. The thermal resistance Junction to Case
is 45⁰C/W. Total power dissipation for the switching regulator and the LDO should be taken in consideration when calculating the output current capability
of each regulator
3
Advanced Monolithic Systems
http://www.ams-semitech.com
AMS3109
Ad
djust (ADJ) Voltage
V
Temperature
Varriation (Adjus
stable Voltag
ge Option)
0.606
Output Voltage Error (%)
Adjust Voltage (V)
Ty
ypical Perfo
ormance Characteris
C
stics (TA = 25°C
2
unless otherwise
o
sp
pecified)
0.604
0.602
0.600
-50
-25
0
25
50
7
75
R
VO = 1.8V, IO = 100mA
Line Regulation
0.2
0.1
0.0
-0.1
-0.2
100 12
25
6
9
Input Voltage (V)
3
Ambient Temperature
e (ºC)
Shutdown Current (µA)
IGND vs
s. Output Currrent VO=1.8V
V, Vin=2.5V
‐50°C
25
20
25°C
15
10
5
100°C
0
0
1
100
200
3
300
400
500
600
Shutd
down Curren
nt vs. Input Voltage
V
50
125°C
40
30
20
25°C
10
0
0
70
00
1
2
3
Outpu
ut Current (A
A)
Output
Voltage
Change (%)
O t tV
lt
Ch
Ground Current (mA)
30
4
0
-0.2
-0.4
-0.6
0.0
5
6
7
8
oltage (V)
Input Vo
Loa
ad Regulation
n
0.2
0.1
Outtput Current (A)
1.0
4
Advanced Monolithic Systems
12
http://www.ams-semitech.com
9 10 11 12
AMS3109
Ty
ypical Perfo
ormance Characteris
C
stics (TA = 25°C
2
unless otherwise
o
sp
pecified)
Dropout Voltage (mV)
Dropout Voltage (mV)
VDO vs. Output
O
Curren
nt
700
600
500
400
100°C
25°C
300
‐50°C
200
100
VOUT = 1.8V
VDO vs. Tempera
ature (IO = 70
00mA)
7
700
6
600
5
500
4
400
3
300
2
200
0
0
1
100
200
300
3
400
5
500
600
700
Outputt Current (mA
A)
-50
0
25
50
75
-25
Ambient Tem
mperature (°C)
Enable Starrt-Up
Load Transient
IOUT = 0 to 350mA, VOUT = 1.8V, VIN = 3.0V, CIN=C
= OUT=10µF
50mA to 550mA
A, VOUT=1.8V, VIN=3.3V CIN= COUT=4.7µF
5
Advanced Monolithic Systems
100
http://www.ams-semitech.com
AMS3109
Functional Block Diagram
Figure 1: Block Diagram of AMS 3109
6
Advanced Monolithic Systems
http://www.ams-semitech.com
AMS3109
Because the ByPass (BYP) pin is high-impedance,
careful considering must be taken in the PCB layout
to minimize noise pickup, and capacitors must be
selected to minimize current leakage.
Current
leakage into the BYP pin will directly affect the
regulator’s accuracy and should be kept low as
possible. Using high quality ceramic and film types
capacitors are recommended for their low leakage
characteristics.
Device Summary
The AMS3109 is a high voltage low drop out linear
regulator with a current capability of up to 700mA. The
LDO has an input voltage range of 1.5V to 12V with
an output voltage as low as 0.6V and is stable with a
wide range of ceramic, tantalum, and electrolytic
output capacitors.
Shutdown/Enable
The enable (on/off) input threshold voltage is 1.1V.
When disabled the LDO quiescent current decreases
to a typical value of <1µA.
Adjustable Feedback Resistor Selection
AMS 3109 uses a 0.6V reference voltage at the
positive terminal of the error amplifier. To set the
output voltage a programming resistor from the adjust
pin (ADJ) to ground must be selected (See Pg.1). A
10kΩ resistor is a good selection for a programming
resistor R2. A higher value may result in an
excessively sensitive feedback node while a lower
value will draw more current and degrade the light
load efficiency. The equation for selecting the voltage
specific resistor is:
Fault Protection
Short circuit and over-temperature shutdown disable
the converter and LDO in the event of an overload
condition. Overtemp shutdown disables the device
when the junction temperature exceeds 145 ºC. The
output current is internally limited to 800mA.
Input Capacitor
An input bypass capacitor ranging from 1µF to 10µF
is required. The capacitor should be placed as close
as possible to the device and not be placed more than
1 inch from the LDO.
R1 =
Vout
Vref
-1 ·R2 =
-1 ·10kΩ = 20kΩ
Table 1: Adjustable Feedback Resistor values
R1 (kΩ)
VOUT (V)
(R2=10kΩ)
1.8
20.0
2.5
31.6
3.3
45.3
5.0
73.2
Output Capacitor
The output capacitor requirements range from the
minimum value required to guarantee stability to a
larger value required to meet the extreme transient
response requirements. Values range from 10 to
22µF X5R ceramic capacitors. Due to the extreme
voltage coefficient of X5R ceramic capacitors, the
voltage rating should be at least double the maximum
applied voltage.
PCB Layout
The following guidelines should be followed to insure
proper layout.
Bypass Capacitor
Whether the LDO is configured to be in a fixed or
adjustable voltage configuration, connecting a
capacitor between the ByPass (BYP) pin and ground
can significantly reduce output noise. Values can
range from 0pF to 10nF, depending on the sensitivity
to output noise in the application. The start-up speed
of the AMS3109 is inversely proportional to the size of
the bypass capacitor. Applications requiring a slow
ramp-up of output voltage should consider larger
values of bypass capacitance. Likewise, if rapid turnon is necessary, consider omitting CBYP.
1. VIN Capacitor. A low ESR ceramic bypass
capacitor must be placed as close to the IC as
possible.
2. Adjustable (ADJ) Feedback Resistors. The
adjustable feedback resistors should be placed as
close as possible the IC. Minimize the length of
the trace from the feedback pin to the resistors.
This is a high impedance node susceptible to
interference from external RF noise sources.
3. Ground.
4. For good thermal performance vias are required
to couple the exposed tab of the SO-8 package to
the PCB ground plane. The via diameter should
be 0.3mm to 0.33mm positioned on a 1.2mm grid.
7
Advanced Monolithic Systems
1.8V
0.6V
http://www.ams-semitech.com
AMS3109
Output Power and Thermal Limits
Tjmax = Pd·θjc + Tpcb + Tamb
The AMS3109 junction temperature and current
capability depends on the internal dissipation and the
junction to case thermal resistance of the SO-8
exposed paddle package.
The internal losses contribute to the junction
temperature rise above the paddle and PCB
temperature.
Additionally, the paddle and PCB temperature will be
elevated due to the total losses of the LDO and of
other circuits mounted to the PCB.
8
Advanced Monolithic Systems
http://www.ams-semitech.com
AMS3109
Figure 2: AMS3109 Evaluation Board
Top Side
Figure 3: AMS3109 Evaluation Board
Bottom Side
2
1
1
C4
10nF
2
3
4
Vin
U1
BYP
EN
NC
NC
GND
ADJ
Enable
8
7
VIN VOUT
6
R1
5
AMS3109
C2
22uF
C1
10uF
C3
n/a
R2
10.0k
gnd
gnd
Vout
Figure 4: AMS3109 Evaluation Board Schematic
Component
C1
C2
C3
C4
1.2V
1.8V
2.5V
3.3V
5.0V
R1
R2
U1
Table 2: AMS3109 Evaluation Board Bill of Materials
Value
Manufacturer Manufacturer Part Number
10µF, 50V, X5R, 1210, Ceramic
22µF, 10V, X5R, 0805, Ceramic
Optional Feedforward
10nF, 50V,20%,X7R,0603
10.0kΩ, 0.1W, 0603 1%
20.0kΩ, 0.1W, 0603 1%
31.6kΩ, 0.1W, 0603 1%
45.3kΩ, 0.1W, 0603 1%
73.2kΩ, 0.1W, 0603 1%
10.0kΩ, 0.1W, 0603 1%
Linear Regulator
Taiyo Yuden
Taiyo Yuden
UMK325BJ106KM-T
LMK212BJ226MG-T
Murata
Various
Various
Various
Various
Various
Various
AMS
GRM188R71H103MA01
CRCW0603xxKxFKEA
CRCW0603xxKxFKEA
CRCW0603xxKxFKEA
CRCW0603xxKxFKEA
CRCW0603xxKxFKEA
CRCW060310K0FKEA
AMS3109 SOIC-8 EDP
9
Advanced Monolithic Systems
http://www.ams-semitech.com
AMS3109
Ordering Information
Device
Package
AMS3109S(1)(2)
SOIC-8 EDP
Notes:
1. Available in tape and reel only. A reel contains 2,500 devices.
2. Available in lead-free package only. Device is fully WEEE and RoHS compliant
Outline Drawing and Landing Pattern
SOIC-8 package dimensions are inches (millimeters) unless otherwise noted.
0.189-0.197*
(4.801-5.004)
8
7
6
8
5
0.228-0.244
(5.791-6.197)
0.123 (3.12)
0.137 (3.48)
7
6
5
0.150-0.157**
(3.810-3.988)
1
2
3
1
4
2
3
4
0.010-0.020 x 45°
(0.254-0.508)
0.053-0.069
(1.346-1.752)
0.004-0.010
(0.101-0.254)
0.014-0.019
(0.355-0.483)
0.024(0.61)
0.090 (2.28)
0.102 (2.59)
0.008-0.010
(0.203-0.254)
0.050
(1.270)
TYP
0°-8° TYP
0.016-0.050
(0.406-1.270)
S ( SO- 8 ) AMS DRW # 042293
*DIMENSION DOES NOT INCLUDE MOLD FLASH. MOLD FLASH
SHALL NOT EXCEED 0.006" (0.152mm) PER SIDE
0.050(1.27)
0.063(1.60)
**DIMENSION DOES NOT INCLUDE INTERLEAD FLASH.
INTERLEAD FLASH SHALL NOT EXCEED 0.010" (0.254mm) PER
SIDE
0.105(2.67)
0.213(5.41)
0.138
(3.50)
RECOMMENDED LAYOUT PATTERN
10
Advanced Monolithic Systems
http://www.ams-semitech.com