Advanced Power
Electronics Corp.
FEATURES
Input Voltage Range : 2.5V to 6V
Varied Fixed Output Voltage Combinations
150mV Dropout at 100mA Output
Current (Vout≧2.8V)
Output Current: 200mA/channel (typ.)
Low Quiescent Current
Standby Current: 2uA (typ.)
Current Limit and Short Current Protections
Thermal Shutdown Protection
Fast Transient Response
Low ESR Capacitor Compatible (X7R, X5R)
Available in the 6-Pin Pb-Free SOT-26
and DFN 2x2 Packages
APE8837
DESCRIPTION
The APE8837 is a high accurately, low noise, high
ripple rejection ratio, low dropout, dual CMOS LDO voltage
regulators with enable function. The EN function allows the
output of each regulator to be turned off independently,
resulting in greatly reduced power consumption.
The APE8837 has the soft start function to suppress
the inrush current. The current limit is over 250mA per
channel and also operates as a short protection for the
output current limiter. The output voltage for each regulator
is set independently by metal trimming.
The APE8837 is fully compatible with low ESR ceramic
capacitors, reducing cost and improving output stability. This
high level output stability is maintained even during frequent
load fluctuations, due to the excellent transient response
performance and high PSRR achieved across a broad range
of frequency. It is available in the SOT-26 and DFN 2x2
packages.
DUAL CHANNEL LDO REGULATORS WITH ENABLE
TYPICAL APPLICATION
V
IN
C
IN
1uF
V
OUT2
C
OUT2
1uF
EN2
V
IN
EN1
V
OUT1
C
OUT1
1uF
VOUT2
VOUT1
GND
APE8837A
ORDERING INFORMATION
Output Type Code : (V
OUT1
+V
OUT2
)
APE8837 X X - HF
Halogen Free
Output Type
(Refer Table)
Package
Y : SOT-26
GN2 : DFN 2x2
A : 1.5V+2.8V
B : 1.8V+2.8V
C : 1.8V+2.6V
D : 1.8V+3.3V
E : 2.5V+2.8V
F : 2.8V+1.2V
G : 2.8V+1.8V
H : 2.8+3.0V
J : 2.8+3.3V
K : 3.0+3.0V
L : 3.0V+3.3V
M : 3.3+3.3V
P : 1.8V+3.0V
Q : 1.5V+2.5V
R : 3.3V+1.8V
T : 1.5V+3.3V
V : 1.5V+3.0V
W : 1.2V+2.8V
X : 1.2V+1.2V
Y : 2.8V+1.5V
Table1.
Data and specifications subject to change without notice
1
201003171
Advanced Power
Electronics Corp.
ABSOLUTE MAXIMUM RATINGS
(at T
A
=25°C)
Input Voltage (VIN) -----------------------------------------
Output Current (I
O1
+I
O2
) -----------------------------------
GND - 0.3 to + 6V
500mA
APE8837
Output Voltage (VOUT1/VOUT2) ----------------------- GND - 0.3 to VIN + 0.3
Enable Voltage (VEN1/VEN2) --------------------------- GND - 0.3 to VIN + 0.3
Power Dissipation (P
D
) ------------------------------------- 250mW
Storage Temperature Range (T
ST
) ---------------------
Operating Temperature Range (T
OP
) ------------------
Junction Temperature Range (T
J
) ----------------------
Thermal Resistance from Junction to case (Rth
jc
)
Thermal Resistance from Junction to ambient (Rth
ja
)
-40 to 150°C
-40 to 85°C
-40 to 125°C
180
o
C/W
250
o
C/W
Note. Rth
ja
is measured with the PCB copper area of approximately 1 in
2
(Multi-layer). That need connect to GND pin.
PACKAGE INFORMATION
VOUT1 GND VOUT2
(Top View)
6
5
4
EN1
VIN
EN2
1
2
3
SOT-26
APE8837
6
VOUT1
5
GND
4
VOUT2
1
GND
2
3
EN1 VIN EN2
DFN 2x2 (6L)
(TOP VIEW)
APE8837
ELECTRICAL SPECIFICATIONS
(T
A
=25℃, unless otherwise noted.)
Parameter
Input Voltage
Output Voltage Accuracy
Quiescent Current
Dropout Voltage
Current Limit (Note2)
Short Circuit Current
Line Regulation
Load Regulation (Note 3)
Ripple Rejection
Output Voltage Temperature Coefficient
SYM
V
IN
∆V
OUT
I
CC
V
DROP
I
LIMIT
I
SC
∆V
LINE
∆V
LOAD
PSRR
V
ENH
V
ENL
I
EN
I
SD
TST
TSH
Note1.
TEST CONDITION
I
OUT
=1mA, V
IN
=5V,V
OUT
>2.0V
I
OUT
=1mA, V
IN
=5V,V
OUT
≦2.0V
I
OUT1,2
=0mA, V
IN
=5V
I
OUT
=0.2A, V
O
=V
O
-2%, V
OUT
=1.5V
I
OUT
=0.2A, V
O
=V
O
-2%, V
OUT
=1.8V
I
OUT
=0.2A, V
O
=V
O
-2%, V
OUT
>2.5V
V
IN
=V
OUT (T)
+ 1.0V, V
EN
=V
IN
V
OUT
<1.0V, each channel
I
OUT
=1mA, V
IN
=V
OUT
+1V to 6.0V
I
OUT
=1~100mA, V
IN
=V
OUT
+1V
F=120Hz, I
OUT
= 30mA
I
OUT
=30mA (Note 4)
MIN
2.5
-2
-0.04
-
-
-
-
250
-
-
-
-
-
2
-
TYP
-
-
-
60
1000
700
300
-
150
0.2
0.01
60
+100
-
-
1
2
150
40
MAX
5.5
2
0.04
100
1200
900
400
-
-
0.3
0.03
-
-
-
0.8
2
4
-
-
UNITS
V
%
V
uA
mV
mA
mA
%/V
%/mA
dB
PPM/ºC
V
uA
uA
ºC
ºC
2
Enable Input Threshold
Enable Pull-high Current
Shutdown Current
Thermal Shutdown Temperature
Thermal Shutdown Hysterisis
V
EN1,2
= 0V
I
OUT1,2
=0mA, V
IN
=5V, V
EN1,2
=0V
-
-
-
-
Advanced Power
Electronics Corp.
Note 1.
V
IN (min)
=V
OUT
+V
DROP
APE8837
Note 2.
Current limit is measured at constant junction temperature by using pulsed testing with a low ON time.
Note 3.
Regulation is measured at constant junction temperature by using pulsed testing with a low ON time.
Note 4.
Guaranteed by design.
PIN DESCRIPTIONS
PIN SYMBOL
VIN
GND
EN1
EN2
VOUT1
VOUT2
PIN DESCRIPTION
Input Voltage
Common Ground Pin
VOUT1 Enable Control Pin
VOUT2 Enable Control Pin
Output1 Voltage
Output2 Voltage
BLOCK DIAGRAM
VIN
Current
Limit2
Thermal
Shutdown
Bandgap
Current
Limit1
-
- +
+
VOUT2
Error
Amp
Enable2
Enable1
Error
Amp
VOUT1
GND
EN2
EN1
FUNCTION DESCRIPTION
The APE8837 is a highly accurate, dual, low noise, CMOS LDO voltage
regulators with enable function. The output voltage for each regulator is set
independently by fuse trimming. As illustrated in function block diagram, it consists of a
reference, error amplifier, a P-channel pass transistor, an ON/OFF control logic and an
internal feedback voltage divider. The band gap reference is connected to the error
amplifier, which compares the reference with the feedback voltage and amplifies the
voltage difference. If the feedback voltage is lower than the reference voltage, the
pass- transistor gate is pulled lower, which allows more current to pass to the V
OUT
pin
and increases the output voltage. If the feedback voltage is too high, the pass
transistor gate is pulled up to decrease the output voltage. The output voltage is feed
back through an internal resistive divider connected to V
OUT
pin. Additional blocks
include an output current limiter, thermal sensor, and shutdown logic.
3
Advanced Power
Electronics Corp.
Enable Function
APE8837
EN1 and EN2 pin start and stop the corresponding outputs independently. When
the EN pin is switched to the power off level, the operation of all internal circuit stops,
the build-in P-channel MOSFET output transistor between pins VIN and VOUT is
switched off, allowing current consumption to be drastically reduced.
Dropout Voltage
A regulator’s minimum input-output voltage differential, or dropout voltage,
determines the lowest usable supply voltage. The APE8837 use a P- channel
MOSFET pass transistor, its dropout voltage is function of drain-to-source on-
resistance R
DS (ON)
multiplied by the load current.
V
DROPOUT
= V
IN
-V
OUT
= R
DS(ON)
x I
OUT
Current Limit
Each channel of APE8837 includes a fold back current limiter. It monitors and
controls the pass transistor’s gate voltage, estimates the output current, and limits the
output current within 250mA.
Thermal Shutdown Protection
Thermal Shutdown protection limits total power dissipation of APE8837. When
the junction temperature exceeds T
J
= +150°C, a thermal sensor turns off the pass
transistor, allowing the IC to cool down. The thermal sensor turns the pass transistor
on again after the junction temperature cools down by 40°C, resulting in a pulsed
output during continuous thermal shutdown conditions.
Thermal shutdown protection is designed to protect the APE8837 in the event of fault
conditions. For continuous operation, the absolute maximum operating junction
temperature rating of T
J
= +125°C should not be exceeded.
APPLICATION INFORMATION
Like any low-dropout regulator, the APE8837 requires input and output
decoupling capacitors. The device is specifically designed for portable applications
requiring minimum board space and smallest components. These capacitors must be
correctly selected for good performance (see Capacitor Characteristics Section).
Please note that linear regulators with a low dropout voltage have high internal loop
gains which require care in guarding against oscillation caused by insufficient
decoupling capacitance.
Input Capacitor
An input capacitance of 1µF is required between input pin and ground directly
(the amount of the capacitance may be increased without limit). The input capacitor
must be located less than 1cm from the device to assure input stability. A lower ESR
capacitor allows the use of less capacitance, while higher ESR type (like aluminum
electrolytic) requires more capacitance. Capacitor types (aluminum, ceramic and
tantalum) can be mixed in parallel, but the total equivalent input capacitance/ ESR
must be defined as above to stable operation. There are no requirements for the ESR
on the input capacitor, but tolerance and temperature coefficient must be considered
when selecting the capacitor to ensure the capacitance will be 1µF over the entire
operating temperature range.
4
Advanced Power
Electronics Corp.
APE8837
Output Capacitor
The APE8837 is designed specifically to work with very small ceramic output
capacitors. A ceramic capacitor (temperature characteristics X7R, X5R) in 1μF is
suitable for the APE8837 application. The recommended minimum capacitance for the
device is 1μF, X5R or X7R dielectric ceramic, between VOUT and GND for stability,
but it may be increased without limit. Higher capacitance values help to improve
transient. The output capacitor's ESR is critical because it forms a zero to provide
phase lead which is required for loop stability.
Thermal Considerations
The APE8837 series can deliver a current of up to 200mA/channel over the full
operating junction temperature range. However, the maximum output current must be
debated at higher ambient temperature to ensure the junction temperature does not
exceed 125°C. With all possible conditions, the junction temperature must be within
the range specified under operating conditions. Power dissipation can be calculated
based on the output current and the voltage drop across regulator.
P
D
= (V
IN
- V
OUT
) I
OUT
+ V
IN
x I
GND
The final operating junction temperature for any set of conditions can be
estimated by the following thermal equation:
P
D (MAX)
= (T
J (MAX)
- T
A
) /
θ
JA
Where T
J (MAX)
is the maximum junction temperature of the die (125°C) and T
A
is
the maximum ambient temperature. The junction to ambient thermal resistance (θ
JA
)
SOT-26 package at recommended minimum footprint is 250°C/W.
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