NJM2891
2ch LOW DROPOUT VOLTAGE REGULATOR
GENERAL DESCRIPTION
The NJM2891 is low dropout voltage regulator designed
for cellular phone application.
Advanced Bipolar technology achieves low noise, high ripple
rejection and low quiescent current.
FEATURES
High Ripple Rejection
70dB typ. (f=1kHz , Vo=3V Version)
Output Noise Voltage
Vno=30µVrms typ.(Cp=0.01µF)
Output capacitor with 1.0µF ceramic capacitor (Vo≥2.7V)
Output Current
Io(max.)=150mA
×
2ch
High Precision Output
Vo±1.0%
Low Dropout Voltage
0.10V typ. (Io=60mA)
ON/OFF Control
(Active High)
Internal Short Circuit Current Limit
Internal Thermal Overload Protection
Bipolar Technology
Package Outline
FFP12-B1 (2.0×2.0×0.85mm)
PIN CONFIGURATION
PIN FUNCTION
1. V
OUT
2
2. V
OUT
2
3. GND
4. CONTROL2
5. V
IN
2
6. V
IN
1
PACKAGE OUTLINE
NJM2891PB1
9
10
11
12
1
8
7
6
5
4
6
5
4
7
8
9
10
11
12
7. CONTROL1
8. V
OUT
1
9. V
OUT
1
10. NOISE BYPASS1
11. NC
12. NOISE BYPASS2
2
3
3
2
1
TOP
BOTTOM
NJM2891PB1
EQUIVALENT CIRCUIT
V
IN
1/ V
IN
2
Cont1/Cont2
Thermal
Protection
Bandgap
Reference
Noise Bypass1 /
Noise Bypass2
V
OUT
1/ V
OUT
2
GND
NJM2891
(Ta=25
°
C)
RATINGS
UNIT
+14
V
+14(*1)
V
300(*2)
mW
−
40
∼
+85
°
C
−
40
∼
+125
°
C
(*1):When input voltage is less than +14V, the absolute maximum control voltage is equal to the input voltage.
(*2):On board. (25mm
×
25mm
×
0.2mm)
ABSOLUTE MAXIMUM RATINGS
PARAMETER
SYMBOL
Input Voltage
V
IN
Control Voltage
V
CONT
Power Dissipation
P
D
Operating Temperature
Topr
Storage Temperature
Tstg
Operating Voltage
V
IN
=+2.5V
∼
+14.0V (In case of Vo<2.1V)
ELECTRICAL CHARACTERISTICS
(1CH/2CH : V
IN
=Vo+1V, C
IN
=0.1
µ
F, Co=1.0uF: Vo
≥
2.7V (Co=2.2uF: Vo
≤
2.6V), Cp=0.01
µ
F, Ta=25
°
C)
PARAMETER
SYMBOL
TEST CONDITION
MIN. TYP. MAX. UNIT
+1.0%
V
Output Voltage
Vo
Io=30mA
-1.0%
−
Quiescent Current
Io=0mA, expect Icont
I
Q
120
180
µ
A
−
Quiescent Current
100
nA
V
CONT
=0V
I
Q(OFF)
−
−
at Control OFF
mA
Output Current
Io
150
200
Vo
−
0.3V
−
Line Regulation
0.10 %/V
∆
Vo/
∆
V
IN
V
IN
=Vo+1V
∼
Vo+6V, Io=30mA
−
−
Load Regulation
0.03 %/mA
∆
Vo/
∆
Io
Io=0
∼
100mA
−
−
Dropout Voltage
Io=60mA
0.10 0.18
V
∆
V
I−O
−
ein=200mVrms,f=1kHz, Io=10mA,
70
dB
Ripple Rejection
RR
−
−
Vo=3V Version
Average Temperature
∆
Vo/
∆
Ta
Ta=0
∼
85
°
C, Io=10mA
±
50
−
−
ppm/
°
C
Coefficient of Output Voltage
f=10Hz
∼
80kHz, Io=10mA,
30
Output Noise Voltage
V
NO
µ
Vrms
−
−
Vo=3V Version
Control Voltage for ON-state V
CONT(ON)
V
1.6
−
−
Control Voltage for OFF-state V
CONT(OFF)
0.6
V
−
−
(*3):The output voltage excludes under 2.1V.
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.
OUTPUT VOLTAGE RANK LIST
Device Name
CH1
NJM2891PB1-2121
2.1V
NJM2891PB1-2725
2.7V
NJM2891PB1-2727
2.7V
NJM2891PB1-2825
2.8V
NJM2891PB1-2828
2.8V
NJM2891PB1-J18
2.85V
NJM2891PB1-2929
2.9V
NJM2891PB1-0328
3.0V
NJM2891PB1-0303
3.0V
NJM2891PB1-3332
3.3V
NJM2891PB1-0521
5.0V
Vout
CH2
2.1V
2.5V
2.7V
2.5V
2.8V
1.8V
2.9V
2.8V
3.0V
3.2V
2.1V
NJM2891
TEST CIRCUIT
A
V
1.0µF *note1
I
OUT
1
V
OUT
1
I
CONT
1
V
V
CONT
1
V
OUT
1
V
OUT
1
CONTROL1
NOISE
BYPASS1
Cp=0.01µF
V
IN
1
0.1µF
A
I
IN
1
V
IN
1
NC
NJM2891
V
IN
2
A
0.1µF
I
IN
2
V
IN
2
NOISE
BYPASS2
CONTROL2
Cp=0.01µF
V
OUT
2
V
OUT
2
GND
A
I
CONT
2
V
V
CONT
2
V
V
OUT
2
I
OUT
2
1.0µF *4
(ceramic)
*4 Vo≤2.6V version: Co=2.2µF(ceramic)
NJM2891
TYPICAL APPLICATION
1
In the case where ON/OFF Control is not required:
V
OUT
1
1.0µF *note1
V
OUT
1
NOISE
BYPASS1
Cp=0.01µF
V
OUT
1
R
CONTROL1
(0~300kΩ)
V
IN
1
0.1µF
V
IN
1
NC
NJM2891
V
IN
2
0.1µF
V
IN
2
R
NOISE
BYPASS2
Cp=0.01µF
(0~300kΩ)
CONTROL2
V
OUT
2
GND
V
OUT
2
V
OUT
2
1.0µF *5
*5 Vo≤2.6V version: Co=2.2µF
Connect control terminal to V
IN
terminal
The quiescent current can be reduced by using a resistance “R”. Instead, it increases the minimum
operating voltage. For further information, please refer to Figure “Output Voltage vs. Control Voltage”.
NJM2891
2
In use of ON/OFF CONTROL:
V
OUT
1
1.0µF *note1
R
(0~300kΩ)
V
OUT
1
V
OUT
1
CONTROL1
NOISE
BYPASS1
Cp=0.01µF
V
IN
1
V
IN
1
0.1µF
NC
NJM2891
V
IN
2
0.1µF
V
IN
2
NOISE
BYPASS2
Cp=0.01µF
CONTROL2
V
OUT
2
GND
R
(0~300kΩ)
V
OUT
2
V
OUT
2
1.0µF *5
*5 Vo≤2.6V version: Co=2.2µF
State of control terminal:
•
“H”
→
output is enabled.
•
“L” or “open”
→
output is disabled.
Noise bypass Capacitance Cp
Noise bypass capacitance Cp reduces noise generated by band-gap reference circuit.
Noise level and ripple rejection will be improved when larger Cp is used.
Use of smaller Cp value may cause oscillation.
Use the Cp value of 0.01uF greater to avoid the problem.
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