RT7297B
4
DS7297B-02 September 2012
www.richtek.com
©
Copyright 2012 Richtek Technology Corporation. All rights reserved. is a registered trademark of Richtek Technology Corporation.
Electrical Characteristics
(V
IN
= 12V, T
A
= 25
°
C, unless otherwise specified)
Absolute Maximum Ratings
(Note 1)
Supply Input Voltage, VIN -----------------------------------------------------------------------------------------
−
0.3V to 20V
Switch Voltage, SW ------------------------------------------------------------------------------------------------
−
0.3V to (V
IN
+ 0.3V)
V
BOOT
−
V
SW
----------------------------------------------------------------------------------------------------------
−
0.3V to 6V
Other Pins Voltage --------------------------------------------------------------------------------------------------
−
0.3V to 20V
Power Dissipation, P
D
@ T
A
= 25
°
C
SOP-8 (Exposed Pad) --------------------------------------------------------------------------------------------- 1.333W
Package Thermal Resistance (Note 2)
SOP-8 (Exposed Pad),
θ
JA
---------------------------------------------------------------------------------------- 75
°
C/W
SOP-8 (Exposed Pad),
θ
JC
--------------------------------------------------------------------------------------- 15
°
C/W
Lead Temperature (Soldering, 10 sec.) ------------------------------------------------------------------------- 260
°
C
Junction Temperature ----------------------------------------------------------------------------------------------- 150
°
C
Storage Temperature Range --------------------------------------------------------------------------------------
−
65
°
C to 150
°
C
ESD Susceptibility (Note 3)
HBM (Human Body Model) ---------------------------------------------------------------------------------------- 2kV
Recommended Operating Conditions
(Note 4)
Supply Input Voltage, VIN ----------------------------------------------------------------------------------------- 4.5V to 18V
Junction Temperature Range --------------------------------------------------------------------------------------
−
40
°
C to 125
°
C
Ambient Temperature Range --------------------------------------------------------------------------------------
−
40
°
C to 85
°
C
Parameter Symbol
Test
Conditions
Min
Typ
Max
Unit
Shutdown Supply Current
V
EN
= 0V
--
0.5
3
μ
A
Supply Current
V
EN
= 3V, V
FB
= 0.9V
--
0.8
1.2
mA
Reference Voltage
V
REF
4.5V
≤
V
IN
≤
18V
0.788
0.8
0.812
V
Error Amplifier
Transconductance
G
EA
Δ
I
C
= ±10
μ
A --
940
--
μ
A/V
High Side Switch
On-Resistance
R
DS(ON)1
--
110
--
m
Ω
Low Side Switch
On-Resistance
R
DS(ON)2
--
90
--
m
Ω
High Side Switch Leakage
Current
V
EN
= 0V, V
SW
= 0V
--
0
10
μ
A
Upper Switch Current Limit
Min. Duty Cycle, V
BOOT
−
V
SW
= 4.8V
--
5.1
--
A
COMP to Current Sense
Transconductance
G
CS
--
4.7
--
A/V
Oscillation Frequency
f
OSC1
1 1.2
1.4
MHz
Short Circuit Oscillation
Frequency
f
OSC2
V
FB
= 0V
--
270
--
kHz
Maximum Duty Cycle
D
MAX
V
FB
= 0.7V
--
78
--
%
Minimum On Time
t
ON
--
100
--
ns
