RT9903 Datasheet, PDF (6/15 Pages) Richtek Technology Corporation – 5 Channel DC/DC Converters IC with High-Efficiency Step-Up

RT9903
Preliminary
Parameter
Symbol
Test Condition
Oscillator
Free Running Frequency
CH1, CH2, CH3 Maximum Duty Cycle
F_OSC
RT = Open
D_MAX1,2,3
CH4 Maximum Duty Cycle
D_MAX4
Reference Voltage (CH1, CH2, CH3, CH4, CH5)
Feedback Reference Voltage
Feedback Reference Voltage
Feedback Voltage (Charge Pump)
Error Amplifier
V_{FB1, 2, 4}
V_FB3
V_FBCP
CH1, CH2, CH4
CH3
CH5
GM
FB1 = COMP
Compensation Source Current
Min Typ Max Units
400 500 600 kHz
93 95 -- %
75 80 85 %
0.98 1 1.02 V
0.18 0.2 0.22 V
-0.02 0 0.02 V
-- 200 -- μs
-- 22 -- μA
Compensation Sink Current
-- 22 -- μA
Power Switch
CH1 On Resistance of MOSFET
CH1 Current Limitation
R_DS1(ON) N-MOSFET, V_DD = 3.3V -- 0.6 -- Ω
0.7 --
--
A
CH2 On Resistance of MOSFET
CH2 Current Limitation
R_DS2(ON) N-MOSFET, V_DD = 3.3V -- 0.6 -- Ω
0.7 --
--
A
CH3 On Resistance of MOSFET
CH3 Current Limitation
R_DS3(ON) N-MOSFET, V_DD = 3.3V -- 0.6 -- Ω
0.7 --
--
A
Charge Pump On Resistance of N-MOSFET
15 20 25 Ω
Charge Pump On Resistance of P-MOSFET
15 20 25 Ω
CH4 Over Current Threshold Voltage
0.3 0.4 0.5 V
CH4 On Resistance of N-MOSFET
3
6
9Ω
CH4 On Resistance of P-MOSFET
-- 20 -- Ω
Control
EN1, EN2, EN3, EN4 Input High Level Threshold
EN1, EN2, EN3, EN4 Input Low Level Threshold
External Current Setting (CH4)
V_VDDM = 3.3V
V_VDDM = 3.3V
-- 0.8 1.3 V
0.4 0.8 -- V
CS4 Sourcing Current
I_CS4
Thermal Protection
8 10 12 μA
Thermal Shutdown
T_SD
-- 180 -- °C
Note 1. Stresses listed as the above “Absolute Maximum Ratings” may cause permanent damage to the device. These are
for stress ratings. Functional operation of the device at these or any other conditions beyond those indicated in the
operational sections of the specifications is not implied. Exposure to absolute maximum rating conditions for extended
periods may remain possibility to affect device reliability.
Note 2. The device is not guaranteed to function outside its operating conditions.
Note 3. θJA is measured in the natural convection at TA = 25°C on a low effective thermal conductivity test board of
JEDEC 51-3 thermal measurement standard.
Note 4. Pull low EN1, EN2 and EN4 when they are not enabled. EN3 pin is automatically pulled low when not enabled.
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6
DS9903-07 August 2007