Rainbow Electronics MAX669 - Manual (Page 3)

V
MAX668/MAX669
1.8V to 28V Input, PWM Step-Up
Controllers in µMAX
_______________________________________________________________________________________ 3
70
100 500 SYNC Input Frequency Range
SYNC/SHDN Falling Edge to Shutdown Delay
2 5 EXT high or low EXT On-Resistance
1 EXT forced to 2V
Ω
EXT Sink/Source Current
1.5 1.8V < V CC < 3.0V (MAX669)
A
SYNC/SHDN Input High Voltage
0.30 1.8V < V CC < 3.0V (MAX669)
µA
SYNC/SHDN Input Low Voltage
0.5 3.0 SYNC/SHDN = 5V
SYNC/SHDN Input Current
1.5 6.5 SYNC/SHDN = 28V
V
MIN TYP MAX CONDITIONS PARAMETER
µs
kHz
UNITS
ELECTRICAL CHARACTERISTICS (continued)
(V CC = LDO = +5V, R OSC = 200k
Ω
, T A = 0°C to +85°C, unless otherwise noted. Typical values are at T A = +25°C.)
ELECTRICAL CHARACTERISTICS
(V CC = LDO = +5V, R OSC = 200k Ω , T A = -40°C to +85°C, unless otherwise noted.) (Note 2)
2.40 2.60
Sensed at LDO, falling edge,
hysteresis = 1%, MAX669 only
LDO Undervoltage Lockout Threshold
2.65 5.50
3V
≤
V CC
≤
28V
(includes LDO dropout)
4.50 5.50
5V ≤ V CC
≤ 28V
(includes LDO dropout)
LDO Output Voltage
Reference and LDO Regulators
V
3 28 MAX668
V
PWM Controller
Input Voltage Range, V CC
6 SYNC/SHDN = GND, V CC = 28V Shutdown Supply Current (V CC )
350 V FB = 1.30V, V CC = 3V to 28V
µA
V CC Supply Current (Note 1)
1 CS+ forced to GND
µA
CS+ Input Current
3 27
µA
Idle Mode Current-Sense Threshold
2.7 5.5
mV
Input Voltage Range with V CC Tied to LDO
1.22 1.28
mV
FB Threshold
20 V FB = 1.30V nA FB Input Current
85 115
V
Current-Limit Threshold
MIN MAX CONDITIONS
V
PARAMETER
V
UNITS
86 90 94 R OSC = 500k Ω ±1%
MAX669
LDO load =
∞ to 400 Ω
1.8 28
3.0V < V CC < 28V
3.0V < V CC < 28V 2.0
0.45
V
200 Not tested SYNC Input Rise/Fall Time ns
50 200 Minimum SYNC Input Low Pulse Width ns
20 45 Minimum SYNC Input-Pulse Duty Cycle %
290 Minimum EXT Pulse Width ns
87 90 93 R OSC = 200k
Ω
±1%
86 90 94 R OSC = 100k
Ω
±1% Maximum Duty Cycle %
PWM CONTROLLER
REFERENCE AND LDO REGULATORS