RT7256B Datasheet, PDF (4/14 Pages) Richtek Technology Corporation – 3A, 17V, 1.2MHz Synchronous Step-Down Converter

RT7256B
Absolute Maximum Ratings (Note 1)
Supply Voltage, V_IN ------------------------------------------------------------------------------------------------- −0.3V to 20V
Switch Voltage, SW ------------------------------------------------------------------------------------------------ −0.3V to (V_IN + 0.3V)
V_BOOT − V_SW ---------------------------------------------------------------------------------------------------------- −0.3V to 6V
Other Pins Voltages ------------------------------------------------------------------------------------------------ −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 Mode) ---------------------------------------------------------------------------------------- 2kV
MM (Machine Mode) ------------------------------------------------------------------------------------------------ 200V
Recommended Operating Conditions (Note 4)
Supply Voltage, V_IN ------------------------------------------------------------------------------------------------- 4.5V to 17V
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
Shutdown Supply Current
V_EN = 0V
Supply Current
V_EN = 3V, V_FB = 0.9V
Reference Voltage
High Side Switch
On-Resistance
Low Side Switch
On-Resistance
High Side Switch Leakage
Current
Upper Switch Current Limit
COMP to Current Sense
Transconductance
Oscillation Frequency
Short Circuit Oscillation
Frequency
Maximum Duty Cycle
Minimum On-Time
V_REF
4.5V ≤ V_IN ≤ 17V
R_DS(ON)1
R_DS(ON)2
G_CS
f_OSC1
f_OSC2
D_MAX
t_ON
V_EN = 0V, V_SW = 0V
Min. Duty Cycle,
V_BOOT − V_SW = 4.8V
V_FB = 0V
V_FB = 0.7V
Min Typ Max Unit
--
0.5
3
μA
--
0.8 1.2 mA
0.788 0.8 0.812 V
--
110
--
mΩ
--
90
--
mΩ
--
0
10
μA
--
5.1
--
A
--
4.7
--
A/V
1000 1200 1400 kHz
--
270
--
kHz
--
78
--
%
--
100
--
ns
Copyright ©2012 Richtek Technology Corporation. All rights reserved.
www.richtek.com
4
is a registered trademark of Richtek Technology Corporation.
DS7256B-00 February 2012