m62291gp Renesas Electronics Corporation., m62291gp Datasheet - Page 4

• Manufacturer Part Number: m62291gp
• Description: 5-pin Sot-23 5.0 V System Fixed Output Voltage Dc/dc Converter
• Manufacturer: Renesas Electronics Corporation.

M62291GP
Application Circuit (5.0 V Output DC/DC Converter; M62291GP)
The Expression of Circuit Constants
Note:
REJ03D0851-0201 Rev.2.01 Nov 14, 2007
Page 4 of 5
Current limit detection:
When the voltage drop between 4-pin and 5-pin becomes 140 mV or more, current limit detection circuit starts to
operate. In the example of application (Figure 1), the current is limited to 1.5 A.
V
Vsat: Output saturation voltage of an external switching transistor.
Choose an external transistor, diode and inductor with peak current rating greater than "Ipk".
I
F
O
:
: Set to 1/3 to 1/5 of maximum output current.
V
Forward voltage drop of an external diode.
OUT
V
100 µF
IN
(12 V)
(5.0 V, 1 A)
+
+
100 µF
Figure 1 Example of Application Circuit of M62291GP
T
(T
T
T
L
lpk
R
T
3
OFF
OFF (MIN)
ON (MAX)
CLM
ON
(MIN)
ON
IN
Constants
+ T
OFF
)
V
MAX
4
CC
M62291
0.09 Ω
R
CLM
0.14
(V
Ipk
f
OSC
IN
1
(T
GND
CLM
− V
5
2
ON
∆V
Collector
f
V
OSC
CE (sat)
+ T
IN
Expressions
CLM
f
l
− V
OSC
O
: 120kHz (V
OFF
1
V
+
: 140mV (V
O
CE (sat)
∆l
) / (
− V
+ V
1
2
− T
O
O
1 +
1
∆l
F
OFF
) × T
O
− V
T
T
CC
1 kΩ
ON
OFF
O
ON (MAX)
CC
= 12V)
1 kΩ
= 12V)
)
150 µH