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%
0.10V typ. (Io=60mA)
"
Low Dropout Voltage
"
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
!
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
(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(*3)
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.
NJM2891
!
TEST CIRCUIT
A
V
1.0µF *4
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 *5
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
NJM2891
2
In use of ON/OFF CONTROL:
V
OUT
1
1.0µF *5
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 0.01
µ
F greater to avoid the problem.
%
In the case of using a resistance "R" between V
IN
and control.
The current flow into the control terminal while the IC is ON state (I
CONT
) can be reduced when a pull up
resistance "R" is inserted between V
IN
and the control terminal.
The minimum control voltage for ON state (V
CONT (ON)
) is increased due to the voltage drop caused by
I
CONT
and the resistance "R". The I
CONT
is temperature dependence as shown in the "Control Current vs.
Temperature" characteristics. Therefore, the resistance "R" should be carefully selected to ensure the
control voltage exceeds the V
CONT (ON)
over the required temperature range.
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