Rainbow Electronics MAX669 - Manual (Page 4)

MAX668/MAX669
1.8V to 28V Input, PWM Step-Up
Controllers in µMAX
4 _______________________________________________________________________________________
ns
% Minimum SYNC Input-Pulse Duty Cycle 45
Minimum SYNC Input Low Pulse Width 200
SYNC Input Rise/Fall Time Not tested 200 ns
ELECTRICAL CHARACTERISTICS (continued)
(V CC = LDO = +5V, R OSC = 200k
Ω
, T A = -40°C to +85°C, unless otherwise noted.)
R OSC = 200k Ω ±1% 87 93
SYNC Input Frequency Range 100 500 kHz
1.8V < V CC < 3.0V (MAX669) 0.30
V
1.8V < V CC < 3.0V (MAX669) 1.5
V
SYNC/SHDN = 28V 6.5
µA
EXT On-Resistance EXT high or low 5 Ω
SYNC/SHDN Input Current
SYNC/SHDN = 5V 3.0
Note 1: This is the V CC current consumed when active but not switching. Does not include gate-drive current.
Note 2: Limits at T A = -40°C are guaranteed by design.
222 278
UNITS PARAMETER CONDITIONS MIN MAX
R OSC = 200k Ω ±1%
% Maximum Duty Cycle
R OSC = 500k Ω ±1% 86 94
425 575 R OSC =100k Ω ±1% kHz Oscillator Frequency
85 115 R OSC = 500k Ω ±1%
R OSC = 100k Ω ±1% 86 94
SYNC/SHDN Input High Voltage
3.0V < V CC < 28V 2.0
SYNC/SHDN Input Low Voltage
3.0V < V CC < 28V 0.45
V REF Output Voltage No load, C REF = 0.22µF 1.22 1.28
mV REF Load Regulation REF load = 0 to 50µA -10
V REF Undervoltage Lockout Threshold Rising edge, 1% hysteresis 1.0 1.2
OSCILLATOR