VFM STEP-UP DC/DC
CONVERTER CONTROLLER
RN5RY202
NO.EA-042-0006
OUTLINE
The RN5RY202 Series are VFM (chopper) Control ICs for step-up DC/DC converter with an external power transis-
tor featuring high output voltage accuracy and low supply current by CMOS process. Each of the RN5RY202
Series ICs consists of a voltage reference unit, an error amplifier, an oscillator, a VFM control circuit and feed back
resistors.
Output voltage is fixed at 2V in the IC.
A low ripple, high efficiency step-up DC/DC converter can be constructed by simply adding an inductor, a diode, a
capacitor, and a drive transistor and feed back resistors.
Although the series have no CE pins unlike RN5RY
××
1A, high voltage (V
OUT
=30V) can be also output by using
external feed back resistors.
FEATURES
• Low Supply Current ............................................................................TYP. 3µA
• Low Temperature-Drift Coefficient of Output Voltage ...................TYP. ±50ppm/˚C
• High Accuracy Output Voltage .........................................................±2.5%
• Low Oscillation Start-up Voltage (no load) ......................................MAX. 0.8V
• Any output voltage can be set with external resistors
• Small Package SOT-23-5 (Mini-Mold)
APPLICATIONS
• Constant voltage power source for battery-powered instruments.
• Constant power source for cameras, camcorders, pagers, and other hand-held communication tools.
• Constant power source for devices that require higher voltages than battery voltages.
BLOCK DIAGRAM
V
DD
2
Oscillator
3
V
OUT
5
EXT
Output
Buffer
–
+
Vref
1
GND
1
RN5RY202
SELECTION GUIDE
In the RN5RY202 Series, the taping type for the ICs can be selected at the user's request.
These selections can be made by designating the part number as shown below:
RN5RY202
×
–
××
←Part
Number
{
↑↑ ↑
ab c
{
↑
d
Code
a
b
20. Designation of Output Voltage (V
OUT
)
V
OUT
is fixed at 2.0V.
2
Designation of Packing Type :
c
A : Taping
C : Antistatic bag (for Samples only)
Designation of Taping Type :
Contents
d
Ex. TR, TL (refer to Taping Specifications ; TR type is prescribed as a standard.)
For example, Taping Type TR, is designated by Part Number RN5RY202A-TR.
PIN CONFIGURATION
• SOT-23-5
5
4
mark side
1
2
3
2
RN5RY202
PIN DESCRIPTION
Pin No.
Symbol
Description
1
2
3
4
5
GND
V
DD
EXT
NC
V
OUT
Ground Pin
Input Pin
External Transistor Drive Pin (CMOS Output)
No Connection
Internal Voltage Output Pin (fixed at 2V)
ABSOLUTE MAXIMUM RATINGS
Symbol
Item
Ratings
Unit
V
DD
V
OUT
V
EXT
I
EXT
P
D
Topt
Tstg
Tsolder
Input Voltage
Output Pin Voltage
EXT Pin Output Voltage
EXT Pin Output Current
Power Dissipation
Operating Temperature
Storage Temperature
Lead Temperature (Soldering)
12
12
–0.3 to V
DD
+0.3
±50
150
–40 to +85
–55 to +125
260˚C 10s (Lead part)
V
V
V
mA
mW
˚C
˚C
ABSOLUTE MAXIMUM RATINGS
Absolute Maximum ratings are threshold limit values that must not be exceeded even for an instant under
any conditions. Moreover, such values for any two items must not be reached simultaneously. Operation
above these absolute maximum ratings may cause degradation or permanent damage to the device. These
are stress ratings only and do not necessarily imply functional operation below these limits.
3
RN5RY202
ELECTRICAL CHARACTERISTICS
• RN5RY202
Symbol
Item
Conditions
MIN.
TYP.
MAX.
Topt=25˚C
Unit
V
OUT
V
IN
I
DD1
Output Voltage
Input Voltage
Supply Current 1
V
IN
=V
DD
=1.9V
1.950
2.000
2.050
10
V
V
µA
EXT No load, V
DD
=1.9V
V
OUT
=1.9V, Test circuits1
EXT No load, V
DD
=1.9V
V
OUT
=2.1V, Test circuits1
V
DD
=1.9V, V
OUT
=1.9V
Test circuits2
V
DD
=1.9V, V
OUT
=1.9V
EXT “H” side, Test circuits2
EXT No load, Test circuits2
I
OUT
=10mA
–40˚C≤Topt≤85˚C
V
DD
=1.9V, V
OUT
=1.9V
V
EXT
=GND, Test circuits3
V
DD
=1.9V, V
OUT
=1.9V
V
EXT
=1.9V, Test circuits4
V
DD
=2V, V
OUT
=10V
Test circuits5
1.5
65
15
25
I
DD2
Supply Curren 2
3
5
µA
f
osc
Duty
Vstart
∆V
OUT
∆Topt
I
EXTH
Maximum Oscillator Frequency
180
kHz
Oscillator Duty Cycle
Oscillator Start-up Voltage
Output Voltage
Temperature Coefficient
EXT “H” Output Current
75
0.7
±50
0.8
%
v
ppm/˚C
–1.5
mA
I
EXTL
EXT “L” Output Current
mA
R
VSET
Voltage Set Resistor
2
MΩ
4
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