Datasheet

austriamicrosystems AG
is now
ams AG
The technical content of this austriamicrosystems datasheet is still valid.
Contact information:
Headquarters:
ams AG
Tobelbaderstrasse 30
8141 Unterpremstaetten, Austria
Tel: +43 (0) 3136 500 0
e-Mail: [email protected]
Please visit our website at www.ams.com
Datasheet
AS1374
D u a l 2 0 0 m A , L o w - N o i s e , H i g h - P S RR , L o w D r o p o u t R e g u l a t o r s
1 General Description
2 Key Features
The AS1374 is a low-noise, low-dropout linear regulator with two
separated outputs. Designed to deliver 200mA continuous output
current at each output pin, the LDOs can achieve a low 120mV
dropout for 200mA load current and are designed and optimized to
work with low-cost, small-capacitance ceramic capacitors.
Preset Output Voltages: 1.2V to 3.6V (in 50mV steps)
An integrated P-channel MOSFET pass transistor allows the devices
to maintain extremely low quiescent current (30µA).
Stable with 1µF Ceramic Capacitor for any Load
The AS1374 uses an advanced architecture to achieve ultra-low
output voltage noise of 20µVRMS and a power-supply rejection-ratio
of better than 85dB (@ 1kHz).
Pull-Down Option in Shutdown (factory set)
@ 100Hz to 100kHz
al
id
Output Noise: 20µVRMS
Power-Supply Rejection Ratio: 85dB @ 1kHz
Guaranteed 200mA output
lv
Low Dropout: 120mV @ 200mA Load
Extremely-Low Quiescent Current: 30µA
Two active-High enable pins allows to switch on or off each output
independently from each other.
am
lc s
on A
te G
nt
st
il
Excellent Load/Line Transient
Overcurrent and Thermal Protection
The AS1374 requires only 1µF output capacitor for stability at any
load.
6-bump WLP Package
The device is available in a 6-bump WLP package.
3 Applications
The devices are ideal for mobile phones, wireless phones, PDAs,
handheld computers, mobile phone base stations, Bluetooth portable
radios and accessories, wireless LANs, digital cameras, personal
audio devices, and any other portable, battery-powered application.
Figure 1. AS1374 - Typical Application Circuit
Input
2V to 5.5V
www.austriamicrosystems.com/LDOs/AS1374
OUT 1
VDD
ca
Te
ch
ni
C1
1µF
6
EN 1
Output1
1.2V to 3.6V
3
2
AS1374
C2
1µF
Output2
1.2V to 3.6V
1
OUT 2
C3
1µF
4
EN 2
5
GND
Revision 1.8
1 - 18
AS1374
Datasheet - P i n A s s i g n m e n t s
4 Pin Assignments
1
2
al
id
Figure 2. Pin Assignments (Top View)
3
AS1374
6
lv
5
am
lc s
on A
te G
nt
st
il
4
4.1 Pin Descriptions
Table 1. Pin Descriptions
Pin Number
1
Pin Name
OUT 2
2
VDD
3
4
5
Regulated Output Voltage 2. Bypass this pin with a capacitor to GND. See Application
Information for capacitor selection.
Input Supply
OUT 1
Regulated Output Voltage 1. Bypass this pin with a capacitor to GND. See Application
Information for capacitor selection.
EN 2
Enable 2. Pull this pin to logic low to disable Regulated Output 2 voltage.
GND
Ground
EN 1
Enable 1. Pull this pin to logic low to disable Regulated Output 1 voltage.
Te
ch
ni
ca
6
Description
www.austriamicrosystems.com/LDOs/AS1374
Revision 1.8
2 - 18
AS1374
Datasheet - A b s o l u t e M a x i m u m R a t i n g s
5 Absolute Maximum Ratings
Stresses beyond those listed in Table 2 may cause permanent damage to the device. These are stress ratings only, and functional operation of
the device at these or any other conditions beyond those indicated in Electrical Characteristics on page 4 is not implied. Exposure to absolute
maximum rating conditions for extended periods may affect device reliability.
Table 2. Absolute Maximum Ratings
Max
Units
Electrical Parameters
VDD to GND
-0.3
7
V
All other pins to GND
-0.3
VDD + 0.3
V
Output Short-Circuit Duration
Input Current (latch-up immunity)
Infinite
-100
100
mA
Norm: JEDEC 78
kV
Norm: MIL 883 E method 3015
Electrostatic Discharge
Electrostatic Discharge HBM
2
Comments
al
id
Min
am
lc s
on A
te G
nt
st
il
Temperature Ranges and Storage Conditions
lv
Parameter
Thermal Resistance JA
201.7
ºC/W
Junction Temperature
+125
ºC
+150
ºC
Storage Temperature Range
-55
Package Body Temperature
5
ºC
85
%
The reflow peak soldering temperature (body
temperature) specified is in accordance with IPC/
JEDEC J-STD-020“Moisture/Reflow Sensitivity
Classification for Non-Hermetic Solid State Surface
Mount Devices”.
Te
ch
ni
ca
Humidity non-condensing
+260
Junction-to-ambient thermal resistance is very
dependent on application and board-layout. In
situations where high maximum power dissipation
exists, special attention must be paid to thermal
dissipation during board design.
www.austriamicrosystems.com/LDOs/AS1374
Revision 1.8
3 - 18
AS1374
Datasheet - E l e c t r i c a l C h a r a c t e r i s t i c s
6 Electrical Characteristics
VIN = VOUT + 0.5V, VOUT = 2.85V, CIN = COUT = 1µF, Typical values are at TAMB = +25ºC (unless otherwise specified). All limits are
guaranteed. The parameters with min and max values are guaranteed with production tests or SQC (Statistical Quality Control) methods.
Table 3. Electrical Characteristics
Parameter
Max
Unit
TAMB
Operating Temperature Range
-40
+85
°C
VIN
Input Voltage Range
2
5.5
V
Output Voltage Accuracy
IOUT
Maximum Output Current
IGND
Ground Current
ILIMIT
Current Limit
Min
IOUT = 1mA, TAMB = +25ºC
-1
IOUT = 100µA to 200mA, TAMB = +25ºC
-1.5
IOUT = 100µA to 200mA
-2.5
Each channel
200
Typ
+1
+1.5
mA
One channel on, IOUT = 50µA
25
One channel on, IOUT = 200mA
50
1
µA
30
55
µA
300
400
mA
2V VOUT  2.5V, IOUT = 100mA
80
150
mV
90
OUT = short
210
am
lc s
on A
te G
nt
st
il
Dropout Voltage
%
+2.5
lv
VOUT
Condition
al
id
Symbol
Both channels on, IOUT = 0.05mA
30
IQ
Quiescent Current
Both channels ON,
VIN = VOUTNOM - 0.1V, IOUT = 0mA
50
VLNR
Line Regulation
VIN = (VOUT +0.5V) to 5.5V, IOUT = 1mA
0.02
%/V
VLDR
Load Regulation
IOUT = 1 to 200mA
0.0005
%/mA
ISHDN
Shutdown Current
OUT 1 and OUT 2 disable
0.01
f = 1kHz, IOUT = 10mA
85
f = 10kHz, IOUT = 10mA
65
f = 100kHz, IOUT = 10mA
50
f = 100Hz to 100kHz, ILOAD = 20mA
20
µV
0.01
µA
PSRR
Ripple Rejection
Output Noise Voltage (RMS)
Enable
Enable Input Bias Current
2
Both channels initially OFF
150
One channel initially OFF
200
ca
Enable Exit Delay
Enable Logic Low Level
0.4
Enable Logic High Level
ni
Thermal Protection
2
1.4
µA
µA
dB
µs
V
V
Thermal Shutdown Temperature
160
ºC
TSHDN
Thermal Shutdown Hysteresis
15
ºC
ch
TSHDN
COUT
Output Capacitor
Load Capacitor Range
0.47
Maximum ESR Load
10
µF
500
m
Te
1. Dropout is defined as VIN - VOUT when VOUT is 100mV below the value of VOUT for VIN = VOUT + 0.5V.
2. Time needed for VOUT to reach 90% of final value.
www.austriamicrosystems.com/LDOs/AS1374
Revision 1.8
4 - 18
AS1374
Datasheet - Ty p i c a l O p e r a t i n g C h a r a c t e r i s t i c s
7 Typical Operating Characteristics
VIN = VOUT + 0.5V, VOUT = 2.85V, CIN = COUT = 1µF, TAMB = 25°C (unless otherwise specified).
2.88
2.88
2.87
2.87
2.85
2.84
2.86
2.85
lv
2.86
al
id
Figure 4. Output Voltage vs. Input Voltage
Output Voltage (V)
Output Voltage (V)
Figure 3. Output Voltage vs. Temperature
2.84
Iload = 1mA
CH1
Iload = 10mA
2.83
am
lc s
on A
te G
nt
st
il
2.83
Iload = 100mA
CH2
Iload = 200mA
2.82
-45 -30 -15
0
15
30
45
60
75
2.82
3.35
90
3.85
Temperature (°C)
4.35
4.85
5.35
Input Voltage (V)
Figure 5. Output Voltage vs. Load Current
Figure 6. Output Voltage vs. Input Voltage - Dropout
2.86
2.88
-40°C
2.87
+25°C
2.84
2.86
Output Voltage (V)
Output voltage (V)
+85°C
2.85
2.84
2.83
2.82
2.82
2.8
2.78
2.76
Iload = 100mA
2.74
2.8
0
25
50
ca
2.81
75
2.72
2.75
100 125 150 175 200
Load Current (mA)
2.9
2.95
3
3.05
ni
100
90
80
PSRR (dB)
100
Te
Dropout Voltage (V)
2.85
Figure 8. PSRR vs. Frequency
ch
125
2.8
Input Voltage (V)
Figure 7. Dropout Voltage vs. Load Current
150
Iload = 200mA
75
50
60
50
40
-40°C
25
70
+25°C
30
+85°C
0
25
50
75
100
125
150
175
200
20
100
Load Current (mA)
www.austriamicrosystems.com/LDOs/AS1374
1000
10000
100000
Frequency (Hz)
Revision 1.8
5 - 18
AS1374
Datasheet - Ty p i c a l O p e r a t i n g C h a r a c t e r i s t i c s
Figure 9. Ground Pin Current vs. Load Current
Figure 10. Ground Pin Current vs. Temperature
30
33
31
30
29
28
27
26
25
-40°C
29
28
al
id
Ground Pin Current (µA)
27
26
+25°C
24
+85°C
23
0
25
50
75
100 125
150
175
25
-45 -30 -15
200
Figure 11. Ground Pin Current vs. Input Voltage;
on, no Load
one Channel
15
30
45
Figure 12. Ground Pin Current vs. Input Voltage;
on, ILOAD = 200mA
50
75
90
one Channel
40
30
20
-40°C
10
+25°C
50
40
30
20
-40°C
10
+25°C
+85°C
0
0
1
2
3
4
+85°C
0
3.35
5
3.85
ni
Figure 13. Ground Pin Current vs. Input Voltage; both Channels
on, no Load
90
90
70
60
Te
50
40
30
20
-40°C
+25°C
10
+85°C
0
0
1
2
3
4
5
80
70
60
50
40
30
20
-40°C
+25°C
10
0
3.35
Input Voltage (V)
www.austriamicrosystems.com/LDOs/AS1374
5.35
100
ch
80
4.85
Figure 14. Ground Pin Current vs. Input Voltage; both Channels
on, ILOAD = 200mA
Ground Pin Current (µA)
100
4.35
Input Voltage (V)
ca
Input Voltage (V)
Ground Pin Current (µA)
60
60
Ground Pin Current (µA)
Ground Pin Current (µA)
60
0
Temperature (°C)
am
lc s
on A
te G
nt
st
il
Load Current (mA)
lv
Ground Pin Current (µA)
32
+85°C
3.85
4.35
4.85
5.35
Input Voltage (V)
Revision 1.8
6 - 18
AS1374
Datasheet - Ty p i c a l O p e r a t i n g C h a r a c t e r i s t i c s
Figure 15. Shutdown Current vs. Input Voltage
Figure 16. Load Regulation vs. Temperature
60
0
40
30
20
10
0
0.5
1
1.5
2
2.5
3
3.5
4
4.5
5
-0.0002
-0.0004
-0.0006
-0.0008
0
15 30
45
75
90
Figure 18. Line Regulation vs. Temperature
0.2
0.15
0.1
0.05
0
-0.05
-0.1
-40°C
Line Regulation (% / V)
0.15
0.1
0.05
0
-0.05
Iload = 1mA
-0.1
Iload = 10mA
+25°C
+85°C
0
25
50
75
-0.2
-45 -30 -15
100 125 150 175 200
15
30
45
60
75
90
VOUT1
10mV/Div
10mV/Div
Figure 20. Load Transient Response near Dropout,
IOUT = 200mA
IOUT1
IOUT1
100mA/Div
Te
VOUT2
ch
ni
Figure 19. Load Transient Response, Crosstalk, between CH1
and CH2, IOUT = 200mA
20µs/Div
www.austriamicrosystems.com/LDOs/AS1374
0
Temperature (°C)
ca
Load Current (mA)
Iload = 200mA
20mV/Div
-0.2
Iload = 100mA
-0.15
100mA/Div
-0.15
VOUT1
60
Temperature (°C)
Figure 17. Line Regulation vs. Load Current
Line Regulation (% / V)
CH2
am
lc s
on A
te G
nt
st
il
Input Voltage (V)
0.2
CH1
-0.001
-0.0012
-45 -30 -15
5.5
al
id
+85°C
lv
+25°C
50
Load Regulation (% / mA)
Shutdown Current (nA)
-40°C
20µs/Div
Revision 1.8
7 - 18
AS1374
Datasheet - Ty p i c a l O p e r a t i n g C h a r a c t e r i s t i c s
al
id
EN1
lv
100µs/Div
am
lc s
on A
te G
nt
st
il
100µs/Div
50mA/Div
IOUT1
1V/Div
VOUT1
500mV/Div
VOUT1
IIN
2V/Div
1V/Div
1V/Div
100mA/Div
EN1
VOUT1
IIN
EN1
Figure 24. Startup of CH1 when CH2 is On
2V/Div
Figure 23. Startup of CH1 when CH2 is Off
100mA/Div
VOUT1
VIN
2V/Div
Figure 22. Shutdown
10mV/Div
Figure 21. Line Transient Response
20µs/Div
Te
ch
ni
ca
20µs/Div
www.austriamicrosystems.com/LDOs/AS1374
Revision 1.8
8 - 18
AS1374
Datasheet - D e t a i l e d D e s c r i p t i o n
8 Detailed Description
8.1 Output Voltage
The AS1374 deliver preset output voltages from 1.2V to 3.6V, in 50mV increments (see Ordering Information on page 17).
8.2 Enable
al
id
Figure 25 shows the block diagram of the AS1374. It identifies the basics of a series linear regulator employing a P-Channel MOSFET as the
control element. A stable voltage reference (REF in Figure 25) is compared with an attenuated sample of the output voltage. Any difference
between the two voltages (reference and sample) creates an output from the error amplifier that drives the series control element to reduce the
difference to a minimum. The error amplifier incorporates additional buffering to drive the relatively large gate capacitance of the series pass Pchannel MOSFET, when additional drive current is required under transient conditions. Input supply variations are absorbed by the series
element, and output voltage variations with loading are absorbed by the low output impedance of the regulator.
lv
The AS1374 feature an active high enable mode to shutdown each output independently. Driving EN 1 low disables Output 1, driving EN 2 low
disables Output 2. The disabled Output enters a high-impedance state.
am
lc s
on A
te G
nt
st
il
Figure 25. AS1374 Block Diagram
-
EN1
VIN
EN2
Enable Logic
CH1
Thermal
Protection
Common
Logic
+
Bandgap
Trimmable
Reference
Overcurrent
Protection CH1
GND
Overcurrent
Protection CH2
Enable Logic
CH2
+
OUT2
-
ni
ca
AS1374
OUT1
8.3 Current Limit
ch
The AS1374 include a current limiting circuitry to monitor and control the P-channel MOSFET pass transistor’s gate voltage, thus limiting the
device output current to 300mA.
Te
Note: See Table 3 on page 4 for the recommended min and max current limits. The output can be shorted to ground indefinitely without
causing damage to the device.
8.4 Thermal Protection
Integrated thermal protection circuitry limits total power dissipation in the AS1374. When the junction temperature (TJ) exceeds +160ºC, the
thermal sensor signals the shutdown logic, turning off the P-channel MOSFET pass transistor and allowing the device to cool down. The thermal
sensor turns the pass transistor on again after the device’s junction temperature drops by 15ºC, resulting in a pulsed output during continuous
thermal-overload conditions.
Note: Thermal protection is designed to protect the devices in the event of fault conditions. For continuous operation, do not exceed the
absolute maximum junction temperature rating of +150ºC.
www.austriamicrosystems.com/LDOs/AS1374
Revision 1.8
9 - 18
AS1374
Datasheet - A p p l i c a t i o n I n f o r m a t i o n
9 Application Information
9.1 Dropout Voltage
Dropout is the input to output voltage difference, below which the linear regulator ceases to regulate. At this point, the output voltage change
follows the input voltage change. Dropout voltage may be measured at different load currents, but is usually specified at maximum output. As a
result, the MOSFET maximum series resistance over temperature is obtained. More generally:
(EQ 1)
al
id
VDROPOUT = ILOAD x RSERIES
Dropout is probably the most important specification when the regulator is used in a battery application. The dropout performance of the
regulator defines the useful “end of life” of the battery before replacement or re-charge is required.
am
lc s
on A
te G
nt
st
il
lv
Figure 26. Graphical Representation of Dropout Voltage
VIN
VOUT
VIN=VOUT(TYP)+0.5V
Dropout
Voltage
VOUT
100mV
VIN
VOUT
ca
VIN
ni
Figure 26 shows the variation of VOUT as VIN is varied for a certain load current. The practical value of dropout is the differential voltage (VOUTVIN) measured at the point where the LDO output voltage has fallen by 100mV below the nominal, fully regulated output value. The nominal
regulated output voltage of the LDO is that obtained when there is 500mV (or greater) input-output voltage differential.
ch
9.2 Efficiency
Te
Low quiescent current and low input-output voltage differential are important in battery applications amongst others, as the regulator efficiency is
directly related to quiescent current and dropout voltage. Efficiency is given by:
V LOAD  I LOAD
Efficiency = -----------------------------------------  100 %
V IN  I Q + I LOAD 
(EQ 2)
Where:
IQ = quiescent current of LDO
www.austriamicrosystems.com/LDOs/AS1374
Revision 1.8
10 - 18
AS1374
Datasheet - A p p l i c a t i o n I n f o r m a t i o n
9.3 Power Dissipation
Maximum power dissipation (PD) of the LDO is the sum of the power dissipated by the internal series MOSFET and the quiescent current
required to bias the internal voltage reference and the internal error amplifier, and is calculated as:
PD  MAX   Seriespass  = I LOAD  MAX   V IN  MAX  – V OUT  MIN   Watts
(EQ 3)
Internal power dissipation as a result of the bias current for the internal voltage reference and the error amplifier is calculated as:
PD  MAX   Bias  = V IN  MAX  I Q Watts
Total LDO power dissipation is calculated as:
PD  MAX   Total  = PD  MAX   Seriespass  + PD  MAX   Bias  Watts
9.4 Junction Temperature
al
id
(EQ 4)
(EQ 5)
lv
Under all operating conditions, the maximum junction temperature should not be allowed to exceed 125°C (unless otherwise specified in the
datasheet). Limiting the maximum junction temperature requires knowledge of the heat path from junction to case (JC°C/W fixed by the IC
manufacturer), and adjustment of the case to ambient heat path (CA°C/W) by manipulation of the PCB copper area adjacent to the IC position.
am
lc s
on A
te G
nt
st
il
Figure 27. Package Physical Arrangements
CS-WLP Package
Package
Chip
Transfer Layer
PCB
Te
ch
ni
ca
Solder Balls
www.austriamicrosystems.com/LDOs/AS1374
Revision 1.8
11 - 18
AS1374
Datasheet - A p p l i c a t i o n I n f o r m a t i o n
Figure 28. Steady State Heat Flow Equivalent Circuit
Package
TC°C
RJC
Ambient
TA°C
PCB/Heatsink
TS°C
RCS
RSA
am
lc s
on A
te G
nt
st
il
lv
Chip
Power
al
id
Junction
TJ°C
Total Thermal Path Resistance:
RJA = RJC + RCS + RSA
(EQ 6)
TJ = (PD(MAX) x RJA) + TAMB ºC
(EQ 7)
Junction Temperature (TJ ºC) is determined by:
9.5 Explanation of Steady State Specifications
9.5.1
Line Regulation
Line regulation is defined as the change in output voltage when the input (or line) voltage is changed by a known quantity. It is a measure of the
regulator’s ability to maintain a constant output voltage when the input voltage changes. Line regulation is a measure of the DC open loop gain
of the error amplifier. More generally:
(EQ 8)
ca
V OUT
Line Regulation = ----------------- and is a pure number
V IN
In practise, line regulation is referred to the regulator output voltage in terms of % / VOUT. This is particularly useful when the same regulator is
available with numerous output voltage trim options.
(EQ 9)
Load Regulation
ch
9.5.2
ni
V OUT
100
Line Regulation = -----------------  ------------- % / V
V IN
V OUT
Te
Load regulation is defined as the change of the output voltage when the load current is changed by a known quantity. It is a measure of the
regulator’s ability to maintain a constant output voltage when the load changes. Load regulation is a measure of the DC closed loop output
resistance of the regulator. More generally:
V OUT
Load Regulation = ----------------- and is units of ohms ()
I OUT
(EQ 10)
In practise, load regulation is referred to the regulator output voltage in terms of % / mA. This is particularly useful when the same regulator is
available with numerous output voltage trim options.
V OUT
100
Load Regulation = -----------------  ------------- % / mA
I OUT V OUT
www.austriamicrosystems.com/LDOs/AS1374
Revision 1.8
(EQ 11)
12 - 18
AS1374
Datasheet - A p p l i c a t i o n I n f o r m a t i o n
9.5.3
Setting Accuracy
Accuracy of the final output voltage is determined by the accuracy of the ratio of R1 and R2, the reference accuracy and the input offset voltage
of the error amplifier. When the regulator is supplied pre-trimmed, the output voltage accuracy is fully defined in the output voltage specification.
When the regulator has a SET terminal, the output voltage may be adjusted externally. In this case, the tolerance of the external resistor network
must be incorporated into the final accuracy calculation. Generally:
R1  R1
V OUT =  V SET  V SET   1 + ---------------------
R2  R2
9.5.4
Total Accuracy
al
id
The reference tolerance is given both at 25°C and over the full operating temperature range.
(EQ 12)
Away from dropout, total steady state accuracy is the sum of setting accuracy, load regulation and line regulation. Generally:
9.6 Explanation of Dynamic Specifications
Power Supply Rejection Ratio (PSRR)
am
lc s
on A
te G
nt
st
il
9.6.1
(EQ 13)
lv
Total % Accuracy = Setting % Accuracy + Load Regulation % + Line Regulation %
Known also as Ripple Rejection, this specification measures the ability of the regulator to reject noise and ripple beyond DC. PSRR is a
summation of the individual rejections of the error amplifier, reference and AC leakage through the series pass transistor. The specification, in
the form of a typical attenuation plot with respect to frequency, shows up the gain bandwidth compromises forced upon the designer in low
quiescent current conditions. Generally:
V OUT
PSRR = 20Log ----------------- dB using lower case  to indicate AC values
V IN
(EQ 14)
Power supply rejection ratio is fixed by the internal design of the regulator. Additional rejection must be provided externally. The AS1374 is
designed to deliver low noise and high PSRR, with low quiescent currents in battery-powered systems. The power-supply rejection is 85dB at
1kHz and 50dB at 100kHz. When operating from sources other than batteries, improved supply-noise rejection and transient response are
achieved by increasing the values of the input and output capacitors. Additional passive LC filtering at the input can provide enhanced rejection
at high frequencies.
9.6.2
Output Capacitor ESR
The series regulator is a negative feedback amplifier, and as such is conditionally stable. The ESR of the output capacitor is usually used to
cancel one of the open loop poles of the error amplifier in order to produce a single pole response. Excessive ESR values may actually cause
instability by excessive changes to the closed loop unity gain frequency crossover point. The range of ESR values for stability is usually shown
either by a plot of stable ESR versus load current, or a maximum value in the datasheet.
ca
Some ceramic capacitors exhibit large capacitance and ESR variations with variations in temperature. Z5U and Y5V capacitors may be required
to ensure stability at temperatures below TAMB = -10°C. With X7R or X5R capacitors, a 1µF capacitor should be sufficient at all operating
temperatures.
Larger output capacitor values (10µF) help to reduce noise and improve load transient-response, stability and power-supply rejection.
Input Capacitor
ni
9.6.3
ch
An input capacitor at VIN is required for stability. It is recommended that a 1.0µF capacitor be connected between the AS1369 power supply
input pin VIN and ground (capacitance value may be increased without limit subject to ESR limits). This capacitor must be located at a distance
of not more than 1cm from the VIN pin and returned to a clean analog ground. Any good quality ceramic, tantalum, or film capacitor may be used
at the input.
9.6.4
Noise
Te
The regulator output is a DC voltage with noise superimposed on the output. The noise comes from three sources; the reference, the error
amplifier input stage, and the output voltage setting resistors. Noise is a random fluctuation and if not minimized in some applications, will
produce system problems.
www.austriamicrosystems.com/LDOs/AS1374
Revision 1.8
13 - 18
AS1374
Datasheet
9.6.5
Transient Response
The series regulator is a negative feedback system, and therefore any change at the output will take a finite time to be corrected by the error
loop. This “propagation time” is related to the bandwidth of the error loop. The initial response to an output transient comes from the output
capacitance, and during this time, ESR is the dominant mechanism causing voltage transients at the output. More generally:
V TRANSIENT = I OUTPUT  R ESR
Units are Volts, Amps, Ohms.
(EQ 15)
al
id
Thus an initial +50mA change of output current will produce a -12mV transient when the ESR=240m. Do remember to keep the ESR within
stability recommendations when reducing ESR by adding multiple parallel output capacitors.
After the initial ESR transient, there follows a voltage droop during the time that the LDO feedback loop takes to respond to the output change.
This drift is approx. linear in time and sums with the ESR contribution to make a total transient variation at the output of:
(EQ 16)
lv
T
V TRANSIENT = I OUTPUT   R ESR + ----------------- Units are Volts, Seconds, Farads, Ohms.

C LOAD
Where:
CLOAD is output capacitor
T= Propagation Delay of the LDO
am
lc s
on A
te G
nt
st
il
This shows why it is convenient to increase the output capacitor value for a better support for fast load changes. Of course the formula holds for
t < “propagation time”, so that a faster LDO needs a smaller cap at the load to achieve a similar transient response. For instance 50mA load
current step produces 50mV output drop if the LDO response is 1µsec and the load cap is 1µF.
There is also a steady state error caused by the finite output impedance of the regulator. This is derived from the load regulation specification
discussed above.
9.6.6
Turn On Time
This specification defines the time taken for the LDO to awake from shutdown. The time is measured from the release of the enable pin to the
time that the output voltage is within 5% of the final value. It assumes that the voltage at VIN is stable and within the regulator min and max limits.
Shutdown reduces the quiescent current to very low, mostly leakage values (<1µA).
9.6.7
Thermal Protection
Te
ch
ni
ca
To prevent operation under extreme fault conditions, such as a permanent short circuit at the output, thermal protection is built into the device.
Die temperature is measured, and when a 160°C threshold is reached, the device enters shutdown. When the die cools sufficiently, the device
will restart (assuming input voltage exists and the device is enabled). Hysteresis of 15°C prevents low frequency oscillation between start-up and
shutdown around the temperature threshold.
www.austriamicrosystems.com/LDOs/AS1374
Revision 1.8
14 - 18
AS1374
Datasheet - P a c k a g e D r a w i n g s a n d M a r k i n g s
10 Package Drawings and Markings
The AS1374 is available in a 6-bump WLP package.
Top through view
am
lc s
on A
te G
nt
st
il
lv
Bottom view (ball side)
al
id
Figure 29. 6-bump WLP Package
Te
ch
ni
ca
ASSH
XXXX
Notes:
1. ccc – Coplanarity
2. All dimensions are in µm.
www.austriamicrosystems.com/LDOs/AS1374
Revision 1.8
15 - 18
AS1374
Datasheet - P a c k a g e D r a w i n g s a n d M a r k i n g s
Revision History
Revision
Date
Owner
Description
Initial revisions
11 Oct, 2011
1.8
12 Dec, 2011
Changes made across the document
afe
Updated equations in Power Dissipation section
Te
ch
ni
ca
am
lc s
on A
te G
nt
st
il
lv
Note: Typos may not be explicitly mentioned under revision history.
al
id
1.7
www.austriamicrosystems.com/LDOs/AS1374
Revision 1.8
16 - 18
AS1374
Datasheet - O r d e r i n g I n f o r m a t i o n
11 Ordering Information
The devices are available as the standard products shown in Table 4.
Table 4. Ordering Information
Marking
Output Voltage 1
Output Voltage 2
Delivery Form
Package
AS1374-BWLT-285
ASSH
2.85V
2.85V
Tape and Reel
6-bump WLP
AS1374-BWLT1833
ASSJ
1.8V
3.3V
Tape and Reel
6-bump WLP
AS1374-BWLT1818
ASSP
1.8V
1.8V
Tape and Reel
AS1374-BWLT1218
ASSK
1.2V
1.8V
Tape and Reel
AS1374-BWLT1214
ASSY
1.2V
1.4V
Tape and Reel
AS1374-BWLT18285
ASSZ
1.8V
2.85V
Tape and Reel
AS1374-BWLT1212
ASSW
1.2V
1.2V
Tape and Reel
6-bump WLP
AS1374-BWLT1827
ASTB
1.8V
2.7V
Tape and Reel
6-bump WLP
1
ASTF
1.5V
3.3V
Tape and Reel
6-bump WLP
ASTG
1.8V
2.0V
Tape and Reel
6-bump WLP
ASTH
1.8V
2.1V
Tape and Reel
6-bump WLP
ASTI
2.5V
3.3V
Tape and Reel
6-bump WLP
____
tbd
tbd
Tape and Reel
6-bump WLP
1
AS1374-BWLT1820
1
AS1374-BWLT1821
1
AS1374-BWLT2533
2
AS1374-BWLT
6-bump WLP
6-bump WLP
6-bump WLP
lv
6-bump WLP
am
lc s
on A
te G
nt
st
il
AS1374-BWLT1533
al
id
Ordering Code
1. On request
2. Non-standard devices from 1.2V to 3.6V are available in 50mV steps.
For more information and inquiries contact http://www.austriamicrosystems.com/contact
Note: All products are RoHS compliant and austriamicrosystems green.
Buy our products or get free samples online at ICdirect: http://www.austriamicrosystems.com/ICdirect
Technical Support is available at http://www.austriamicrosystems.com/Technical-Support
Te
ch
ni
ca
For further information and requests, please contact us mailto:[email protected]
or find your local distributor at http://www.austriamicrosystems.com/distributor
www.austriamicrosystems.com/LDOs/AS1374
Revision 1.8
17 - 18
AS1374
Datasheet - O r d e r i n g I n f o r m a t i o n
Copyrights
Copyright © 1997-2011, austriamicrosystems AG, Tobelbaderstrasse 30, 8141 Unterpremstaetten, Austria-Europe. Trademarks Registered ®.
All rights reserved. The material herein may not be reproduced, adapted, merged, translated, stored, or used without the prior written consent of
the copyright owner.
All products and companies mentioned are trademarks or registered trademarks of their respective companies.
al
id
Disclaimer
lv
Devices sold by austriamicrosystems AG are covered by the warranty and patent indemnification provisions appearing in its Term of Sale.
austriamicrosystems AG makes no warranty, express, statutory, implied, or by description regarding the information set forth herein or regarding
the freedom of the described devices from patent infringement. austriamicrosystems AG reserves the right to change specifications and prices at
any time and without notice. Therefore, prior to designing this product into a system, it is necessary to check with austriamicrosystems AG for
current information. This product is intended for use in normal commercial applications. Applications requiring extended temperature range,
unusual environmental requirements, or high reliability applications, such as military, medical life-support or life-sustaining equipment are
specifically not recommended without additional processing by austriamicrosystems AG for each application. For shipments of less than 100
parts the manufacturing flow might show deviations from the standard production flow, such as test flow or test location.
ca
Contact Information
am
lc s
on A
te G
nt
st
il
The information furnished here by austriamicrosystems AG is believed to be correct and accurate. However, austriamicrosystems AG shall not
be liable to recipient or any third party for any damages, including but not limited to personal injury, property damage, loss of profits, loss of use,
interruption of business or indirect, special, incidental or consequential damages, of any kind, in connection with or arising out of the furnishing,
performance or use of the technical data herein. No obligation or liability to recipient or any third party shall arise or flow out of
austriamicrosystems AG rendering of technical or other services.
Headquarters
ni
austriamicrosystems AG
Tobelbaderstrasse 30
A-8141 Unterpremstaetten, Austria
ch
Tel: +43 (0) 3136 500 0
Fax: +43 (0) 3136 525 01
Te
For Sales Offices, Distributors and Representatives, please visit:
http://www.austriamicrosystems.com/contact
www.austriamicrosystems.com/LDOs/AS1374
Revision 1.8
18 - 18