R1230D251B-TL RICOH [RICOH electronics devices division], R1230D251B-TL Datasheet - Page 8

• Manufacturer Part Number: R1230D251B-TL
• Description: PWM/VFM Step-down DC/DC Converter with Synchronous Rectifier
• Manufacturer: RICOH [RICOH electronics devices division]

1) Fixed Output Voltage Type
2) Adjustable Output Voltage Type
Standard value of the sum of Divider Resistors, R1+R2 is as much as 100k .
Cb value for phase compensation depends on values of L, C, and R1. Refer to the technical notes.
If a ceramic capacitor is used as an output capacitor, add 0.2 or more resistance to compensate the ESR of the
capacitor.
Rev. 1.12
When you use these ICs, consider the following issues;
TYPICAL APPLICATION AND TECHNICAL NOTES
Input same voltage into Power Supply pins, V
L
C
C
L:
C
C
When you control the CE pin and MODE pin by another power supply, do not make its "H" level more than the
voltage level of V
Set external components such as an inductor, C
wiring to V
At stand by mode, (CE=”L”), the Lx output is Hi-Z, or both P-channel transistor and N-channel transistor of Lx pin
turn off.
Use an external capacitor C
such as tantalum capacitors.
At VFM mode, (MODE=”H”), Latch protection circuit does not operate.
OUT
IN
OUT
IN
:
: 10 H LQH3C100K54(Murata)
:
: 10 F C3216JB0J106M(TDK)
: 10 F ECSTOJX106R(Panasonic)
C
C
IN
IN
IN
pin and PGND pin.
10 H LQH3C100K54 (Murata)
10 F ECSTOJX106R (Panasonic)
10 F C3216JB0J106M (TDK)
IN
/ V
DD
pin.
PGND
PGND
V
V
CE
V
V
CE
OUT
DD
IN
DD
IN
with a capacity of 10 F or more, and with good high frequency characteristics
MODE
V
MODE
AGND
AGND
V
FB
IN
OUT
L
Lx
X
and V
IN
, C
- 8 -
OUT
DD
. Set the same level as AGND and PGND.
as close as possible to the IC, in particular, minimize the
L
L
Cb
Rb
C
R1
OUT
R 2
C
OUT
V
LOAD
OUT
V
LOAD
OUT