RT7237B Datasheet, PDF (4/15 Pages) Richtek Technology Corporation – 2A, 18V, 1.2MHz Synchronous Step-Down Converter

RT7237B
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
Electrical Characteristics
(VIN = 12V, TA = 25°C, unless otherwise specified)
Parameter
Symbol
Test Conditions
Min Typ Max Unit
Shutdown Supply Current
V_EN = 0V
--
0.5
3
μA
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
ΔI_C = ±10μA
-- 940 -- μA/V
High Side Switch
On-Resistance
R_DS(ON)1
-- 150 -- mΩ
Low Side Switch
On-Resistance
R_DS(ON)2
-- 130 -- mΩ
High Side Switch Leakage
Current
V_EN = 0V, V_SW = 0V
--
0
10 μA
Upper Switch Current Limit
Min. Duty Cycle, V_BOOT − V_SW = 4.8V --
4
--
A
COMP to Current Sense
Transconductance
G_CS
--
3.7
--
A/V
Oscillation Frequency
Short Circuit Oscillation
Frequency
f_OSC1
f_OSC2
V_FB = 0V
1
1.2 1.4 MHz
-- 270 -- kHz
Maximum Duty Cycle
Minimum On Time
D_MAX
t_ON
V_FB = 0.7V
--
78
--
%
-- 100 --
ns
Copyright ©2012 Richtek Technology Corporation. All rights reserved.
www.richtek.com
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is a registered trademark of Richtek Technology Corporation.
DS7237B-01 September 2012