Step-down DC/DC Converter
with VR and Reset
NO. EA-102-0301
OUTLINE
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FEATURES
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R5210x
BLOCK DIAGRAM
Current Limit
CONTROL
VIN
OSC
VOUT1
LX
+
-
OUTPUT
CONTROL
+
Vref
Soft Start
Current Limit
-
Vref
U.V.L.O.
+
VOUT2
Vref
Delay Circuit
+
VDOUT
-
GND
SELECTION GUIDE
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Code
Contents
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R5210x
PIN CONFIGURATIONS
• SOT-23-6W
• HSON-6
6
4
5
6
2
4
(Mark side)
(Mark side)
1
5
3
1
R5210Nxxxx
2
3
R5210Dxxxx
PIN DESCRIPTION
Pin No.
Symbol
Description
R5210N
R5210D
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Rating
Unit
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R5210x
ELECTRICAL CHARACTERISTICS
• R5210N001C
Symbol
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Item
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Typ.
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DC/DC Part
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R5210x
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TYPICAL APPLICATION AND APPLICATION HINTS
• R5210NxxxC
C3
VOUT2
VDOUT
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R1
VOUT2
VIN
VDOUT
GND
VOUT1
LX
C1
C2
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L1
D1
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R5210x
OPERATION of step-down DC/DC converter and Output Current
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R5210x
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R5210x
Timing Chart
(-VDET+VHYS)
-VDET
VUVLO2
VUVLO1
VIN Voltage
Soft-start
Time
VOUT1 Voltage
LX Voltage
VD Delay
for Release
VD Delay
for Release
VDOUT Voltage
VOUT2 Voltage
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(2) Voltage Detector
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R5210x
(3) Voltage Regulator
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TEST CIRCUITS
A) Supply Current
B)
UVLO Detector Threshold/ Released Voltage
OSCILLOSCOPE
VIN
VIN
A
LX
VOUT1
VOUT1
GND
GND
C) Lx Leakage Current
VIN
D) Lx On Resistance
LX
VOUT1
VIN
A
LX
VOUT1
GND
V
GND
E) Lx Current Limit
F)
VOUT1 Output Voltage
OSCILLOSCOPE
OSCILLOSCOPE
VIN
LX
VIN
VOUT1
LX
VOUT1
VOUT2
GND
10
GND
R5210x
G) Oscillator Frequency, Soft-start Time
OSCILLOSCOPE
VIN
OSCILLOSCOPE
VOUT1
LX
VOUT1
GND
H) VOUT2 Output Voltage, Load Regulation, Dropout
I)
Voltage, Current Limit, Short Current Limit
VIN
VDOUT Detector Threshold, Hysteresis Range,
VD Output Delay Time for Release
VIN
LX
VOUT1
LX
VOUT1
VOUT2
GND
V
IOUT2
J)
GND
VDOUT
OSCILLOSCOPE
VDOUT “L” Output Current
VIN
VOUT1
GND VDOUT
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R5210x
TYPICAL CHARACTERISTICS
1)
Output Voltage vs. Output Current
2)
Efficiency vs. Output Current
R5210N001C
R5210N001C
L1=22µH, C1=10µF
VOUT1=2.7V, IOUT2=0mA
L1=22µH, C1=10µF
VOUT1=2.7V, IOUT2=0mA
2.75
Efficiency η(%)
Output Voltage VOUT1(V)
2.8
2.7
VIN=4.5V
VIN=5.0V
VIN=5.5V
2.65
2.6
0
100
200
300
400
100
90
80
70
60
50
40
30
20
10
0
500
VIN=4.5V
VIN=5.0V
VIN=5.5V
0
Output Current IOUT1(mA)
3)
100
4)
R5210N001C
R5210N001C
Output Voltage VOUT2(V)
Output Voltage VOUT1(V)
2.70
2.65
-25
0
25
50
75
3.45
3.40
3.35
3.30
-50
100
-25
Temperature Topt(˚C)
Detector Threshold vs. Temperature
6)
25
50
75
100
Oscillator Frequency vs. Temperature
R5210N001C
R5210N001C
1000
Frequency fosc(kHz)
Detector Threshold-VDET(V)
0
Temperature Topt(˚C)
4.4
4.3
4.2
4.1
-25
0
25
50
Temperature Topt(˚C)
12
500
3.50
2.75
4.0
-50
400
VR Output Voltage vs. Temperature
2.80
5)
300
Output Current IOUT1(mA)
DC/DC Output Voltage vs. Temperature
2.60
-50
200
75
100
900
800
700
600
-50
-25
0
25
50
Temperature Topt(˚C)
75
100
R5210x
7)
Soft-start time vs. Temperature
8)
Output Delay Time for Release VD vs. Temperature
R5210N001C
Soft-start Time TSS(msec)
Output Delay Time for Release VD
tPLH(msec)
R5210N001C
4.0
20
16
3.0
12
2.0
1.0
0.0
-50
-25
0
25
50
75
100
8
4
0
-50
Temperature Topt(˚C)
9)
0
25
50
75
100
Temperature Topt(˚C)
VR Output Voltage vs. Output Current
10) VR Output Voltage vs. Output Current (zoomed)
R5210N001C
R5210N001C
4
3.43
3.5
Output Voltage VOUT2(V)
Output Voltage VOUT2(V)
-25
3
2.5
2
1.5
1
0.5
0
3.42
3.41
3.4
3.39
3.38
3.37
3.36
0
50
100
150
200
250
300
0
Output Current IOUT2(mA)
50
100
150
200
Output Current IOUT2(mA)
11) Load Transient Response 1
12) Load Transient Response 2
L1=22µH, C1=10µF
VOUT1=2.7V
L1=22µH, C1=10µF
VOUT1=2.7V
IOUT1=200mA
IOUT1=200mA
1
IOUT1=10mA
IOUT1=10mA
1
2
2
Ch1 500mV
Ch2 100mV
M 50.0µs Ch1
200mV
Ch1 500mV
Ch2 100mV
M 200µs Ch1
200mV
13