Rainbow Electronics MAX8668 - Manual (Page 3)

MAX8667/MAX8668
1.5MHz Dual Step-Down DC-DC Converters
with Dual LDOs and Individual Enables
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Note 1: All devices are 100% production tested at T A = +25°C. Limits over the operating temperature range are guaranteed by design.
PARAMETER CONDITIONS MIN TYP MAX UNITS
Maximum Adjustable Output
Voltage
MAX8668 3.3 V
T A = +25°C 0.588 0.600 0.612
FB1, FB2 Regulation Voltage
MAX8668, no load,
V
FB_
falling T A = -40°C to +85°C 0.582 0.600 0.618
V
T A = +25°C 1.274 1.300 1.326
OUT1, OUT2 Regulation Voltage
MAX8667ETEJS+, no load, V OUT_
falling T A = -40°C to +85°C 1.261 1.300 1.339
V
FB1, FB2 Line Regulation MAX8668, V IN12 = 2.6V to 5.5V 0.01 %/V
OUT1, OUT2 Line Regulation MAX8667, V IN12 = 2.8V to 5.5V 0.05 %/V
MAX8668, shutdown mode 0.1
FB1, FB2 Bias Current
MAX8668, V FB1 = 0.5V 0.01
µA
pMOSFET switch (I LIMP1 ) 700 900 1100
OUT1 Current Limit
nMOSFET rectifier (valley current) 500 750 1000
mA
pMOSFET switch (I LIMP2 ) 1333 1667 2000
OUT2 Current Limit
nMOSFET rectifier (valley current) 1200 1500 1800
mA
pMOSFET switch, I LX1 = -400mA 0.3 0.6
OUT1 On-Resistance
nMOSFET rectifier, I LX1 = 400mA 0.3 0.6
Ω
pMOSFET switch, I LX2 = -400mA 0.12 0.27
OUT2 On-Resistance
nMOSFET rectifier, I LX2 = 400mA 0.12 0.27
Ω
Rectifier-Off Current Threshold
(I
LXOFF )
60 120 mA
T A = +25°C -1 +1
LX Leakage Current LX_ = 5.5V
T A = +85°C 0.1
µA
Minimum On-Time 100 ns
Minimum Off-Time 50 ns
LDO REGULATORS
Supply Current Each LDO 20 µA
1mA load, T A = +25°C -1.5 +1.5
Output-Voltage Accuracy
1mA to 300mA load -3.0 +3.0
%
Line Regulation V IN34 = 3.6V to 5.5V, 1mA load 0.003 %/V
Dropout Voltage V IN34 = 1.8V, 300mA load 130 250 mV
Current Limit V OUT3 , V OUT4 90% of nominal value 375 420 465 mA
Soft-Start Ramp Time To 90% of final value 0.1 ms
Output Noise 100Hz to 100kHz, 30mA load, V OUT3 and V OUT4 = 2.8V 75 µV RMS
Power-Supply Rejection Ratio f < 1kHz, 30mA load 57 dB
Shutdown Output Resistance 1 k Ω
TIMING (See Figure 2)
OUT1, OUT2 25
Power-On Time (t
PWRON
)
OUT3, OUT4 45
µs
OUT1, OUT2 15
Enable Time (t EN )
OUT3, OUT4 35
µs
ELECTRICAL CHARACTERISTICS (continued)
(V IN34 = V IN12 = 3.6V, T A = -40°C to +85°C, unless otherwise noted. Typical values are at T A = +25°C.) (Note 1)