NJM2827
Negative Output Low Drop Out voltage regulator
GENERAL DESCRIPTION
The NJM2827 is a negative output low dropout regulator.
Advanced bipolar technology achieves low noise, high precision
voltage and high ripple rejection.
It has soft-start and shunt SW function. 1.0µF Output capacitor
and small package can make NJM2827 suitable for portable items.
FEATURES
Low Dropout Voltage
:0.13V (typ.) @Io=60mA
High Precision Output
:±1.5%
High Ripple Rejection
:65dB(typ.) @f=1kHz, Vo=-7V Version
Output capacitor with 1.0µF ceramic capacitor.
Output Current
:Io(max.)=100mA
Soft-start Function
Shunt SW Function
Internal Thermal Overload Protection
Internal Short Circuit Current Limit
Bipolar Technology
Package Outline
SC88A
PIN CONFIGURATION
5
4
1.GND
2.V
IN
3.V
OUT
4.NC
5.CS
PACKAGE OUTLINE
NJM2827F3
1 2 3
NJM2827F3-XX
EQUIVALENT CIRCUIT
GND
Thermal
Protection
CS
Bandgap
Reference
Current
Limit
V
IN
V
OUT
Ver.2010-07-13
-1-
NJM2827
OUTPUT VOLTAGE RANK LIST
Device Name
NJM2827F3 -14
NJM2827F3 -15
NJM2827F3 -05
NJM2827F3 -06
NJM2827F3 -07
NJM2827F3 -75
NJM2827F3 -08
NJM2829F3 -10
V
out
-1.4V
-1.5V
-5.0V
-6.0V
-7.0V
-7.5V
-8.0V
-10.0V
Output voltage options available: -1.5 ~ -10.0V
ABSOLUTE MAXIMUM RATINGS
PARAMETER
SYMBOL
Input Voltage
V
IN
Power Dissipation
P
D
Operating
Topr
Temperature
Storage Temperature
Tstg
(Ta=25°C)
UNIT
V
mW
°C
RATINGS
-14
250(*1)
−40 ∼
+85
°C
−40 ∼
+125
(*1):
Mount on EIA/JEDEC STANDARD Test board (76.2*114.3*1.6mm, 2layers, FR-4)
Operating voltage
V
IN
=-3.2
∼
-12V (In case of Vo>-3.0V version)
ELECTRICAL CHARACTERISTICS
(Vo<-2.2V Version: V
IN
=Vo-1V, C
IN
=0.1µF, Co=1.0µF, Ta=25°C)
(Vo≥-2.2V Version: V
IN
=-3.2V, C
IN
=0.1µF, Co=2.2µF(Vo>-2.0V: Co=4.7µF), Ta=25°C)
PARAMETER
SYMBOL
TEST CONDITION
MIN.
Output Voltage
Vo
Io=30mA
+1.5%
Quiescent Current
I
Q
Io=0mA
-
Output Current
Io
V
O
+0.3V
100
V
IN
=Vo-1V
∼
-12V(V
O
<
-2.2V)
-
Line Regulation
∆Vo/∆V
IN
V
IN
=-3.2V
∼
-12V(V
O
≥
-2.2V)
Io=30mA
Load Regulation
-
∆Vo/∆Io
Io=0∼60mA
Io=60mA
-
Dropout Voltage(*2)
∆V
I_O
V
IN
=Vo-1V
∼
-12V(V
O
≤
-3.0V)
V
IN
=-4.0V
∼
-12V(V
O
>
-3.0V)
Ripple Rejection
RR
-
ein=200mVrms, f=1kHz, Io=10mA,
Vo=-7V Version
Average Temperature
-
Coefficient of Output
∆Vo/∆Ta
Ta=0
∼
85°C, Io=10mA
Voltage
f=10Hz∼80kHz, Io=10mA,
Output Noise Voltage
V
NO
-
Vo=-7V Version
CS Terminal Charge Current Ics
V
CS
=0V
4
Input Voltage
V
IN
-12
(*2): Excludes Vo>-3.0V version.
The above specification is a common specification for all output voltages.
Therefore, it may be different from the individual specification for a specific output voltage.
TYP.
-
130
130
-
-
0.13
65
MAX.
-1.5%
200
-
0.10
0.03
0.23
-
UNIT
V
µA
mA
%/V
%/mA
V
dB
±50
100
5
-
-
-
6
-
ppm/°C
µVrms
µA
V
-2-
Ver.2010-07-13
NJM2827
TEST CIRCUIT
V
IN
0.1µF
A
GND
I
Q
(Ceramic)
I
OUT
1.0µF
*3
V
OUT
V
V
OUT
V
IN
Cs=0.047µF
NJM2827
CS
*3
-2.2V≤Vo≤-2.0V version: Co=2.2µF(Ceramic)
Vo>-2.0V version: Co=4.7µ F(Ceramic)
Ver.2010-07-13
-3-
NJM2827
TYPICAL APPLICATIONS
0.1µF
(Ceramic)
1.0µF
*4
V
IN
V
IN
GND
V
OUT
V
OUT
Cs=0.047µF
NJM2827
CS
CS
*4
-2.2V≤Vo≤-2.0V version: Co=2.2µF(Ceramic)
Vo>-2.0V version: Co=4.7µ F(Ceramic)
Input Capacitance C
IN
Input capacitance C
IN
is required to prevent oscillation and reduce power supply ripple for applications with high
power supply impedance or a long power supply line.
Use the C
IN
value of 0.1µF greater to avoid the problem.
C
IN
should connect between GND and V
IN
as short as possible.
Output Capacitance C
O
Output capacitor (Co) is required for a phase compensation of the internal error amplifier. The capacitance and the
equivalent series resistance (ESR) influences stability of the regulator.
This product is designed to work with a low ESR capacitor for the Co; however, use of recommended capacitance or
greater value is essential for stable operation.
Use of a smaller Co may cause excess output noise or oscillation of the regulator due to lack of the phase
compensation.
Therefore, use Co with the recommended capacitance or greater value and connect between Vo terminal and GND
terminal with minimal wiring. The recommended capacitance depends on the output voltage. Low voltage regulator
requires greater value of the Co. Thus, check the recommended capacitance for each output voltage.
Use of a greater Co reduces output noise and ripple output, and also improves transient response of the output
voltage against rapid load change.
-4-
Ver.2010-07-13
NJM2827
Soft-start function
Capacitance Cs connect between CS pin and GND for the following.
•
Control at risetime of output voltage.
•
Reduces inrush current
at output ON.
When the soft start function is not used, CS pin should be open.
1.Cs capacitance vs risetime of output voltage
Calculation : risetime of output voltage
∆t
≅
213 x Cs(µF)
Cs capacity vs risetime of output voltage
250
risetime of output voltage :
∆t
(mS)
200
150
100
@:Ta=25
o
C
V
IN
=6V
C
IN
=0.1µF
Co=1µF(Ceramic)
Io=0mA
50
0
0
0.2
0.4
0.6
0.8
1
1.2
Cs capacity : Cs(µF)
2.Inrush current
at control ON
The peak value of the inrush current can be limited according to the capacitance of the Cs.
Inrush current wave :
Output Voltage
Inrush current
Output Voltage
Inrush current
Vin=Vo-1V
Cin=0.1µF(Ceramic)
Co=1µF(Ceramic)
Io=0mA
50mA/div
Vin=Vo-1V
Cin=0.1µF(Ceramic)
Co=1µF(Ceramic)
Io=0mA
20mA/div
Cs=0µF(Open) : I
PEAK
=150µA
Inrush Peak Current=150mA(Cs=Open)
Cs=0.0047µF : I
PEAK
=20µA
Inrush Peak Current=20mA(Cs=0.0047
µ
F)
٭
This characteristic is one example. It is necessary to examine the characteristic with an actual circuit
because there is an influence by the characteristic such as output voltage/output capacitor.
Ver.2010-07-13
-5-
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