Rainbow Electronics MAX669 User Manual
Page 2
MAX668/MAX669
1.8V to 28V Input, PWM Step-Up
Controllers in µMAX
2
_______________________________________________________________________________________
ABSOLUTE MAXIMUM RATINGS
ELECTRICAL CHARACTERISTICS
(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.)
V
CC
to GND ..........................................................-0.3V to +30V
PGND to GND....................................................................±0.3V
SYNC/
SHDN to GND .............................................-0.3V to +30V
EXT, REF to GND.....................................-0.3V to (V
LDO
+ 0.3V)
LDO, FREQ, FB, CS+ to GND ................................ -0.3V to +6V
LDO Output Current...........................................-1mA to +20mA
REF Output Current..............................................-1mA to +1mA
LDO Short Circuit to GND .........................................Momentary
REF Short Circuit to GND ..........................................Continuous
Continuous Power Dissipation (T
A
= +70°C)
10-Pin µMAX (derate 5.6mW/°C above +70°C) ..........444mW
Operating Temperature Range ...........................-40°C to +85°C
Junction Temperature ......................................................+150°C
Storage Temperature Range .............................-65°C to +150°C
Lead Temperature (soldering,10sec) ..............................+300°C
85
100
115
425
500
575
225
250
275
R
OSC
= 200k
Ω
±1%
Oscillator Frequency
Oscillator
1.0
1.1
1.2
Rising edge, 1% hysteresis
REF Undervoltage Lockout Threshold
-2
-10
REF load = 0 to 50µA
REF Load Regulation
1.225
1.250
1.275
No load, C
REF
= 0.22µF
REF Output Voltage
2.40
2.50
2.60
Sensed at LDO, falling edge,
hysteresis = 1%, MAX668 only
Undervoltage Lockout Threshold
2.65
5.50
3V
≤
V
CC
≤
28V
(includes LDO dropout)
4.50
5.00 5.50
LDO Output Voltage
Reference and LDO Regulators
3
28
MAX668
PWM Controller
Input Voltage Range, V
CC
3.5
6
SYNC/SHDN = GND, V
CC
= 28V
Shutdown Supply Current (V
CC
)
220
350
V
FB
= 1.30V, V
CC
= 3V to 28V
V
CC
Supply Current (Note 1)
0.2
1
CS+ forced to GND
CS+ Input Current
5
15
25
Idle Mode Current-Sense Threshold
2.7
5.5
Input Voltage Range with V
CC
Tied to LDO
1.225
1.250
1.275
FB Threshold
1
20
V
FB
= 1.30V
FB Input Current
85
100
115
Current Limit Threshold
MIN
TYP MAX
CONDITIONS
PARAMETER
kHz
V
mV
V
V
V
µA
µA
µA
mV
mV
nA
V
V
V
UNITS
MAX669
1.8
28
LDO load =
∞
to 400
Ω
5V
≤
V
CC
≤
28V
(includes LDO dropout)
R
OSC
= 500k
Ω
±1%
R
OSC
= 100k
Ω
±1%
0.013
Typically 0.013% per mV on CS+;
V
CS
+ range is 0 to 100mV for 0 to full
load current.
FB Threshold Load Regulation
%/mV
0.012
Typically 0.012% per % duty factor on
EXT; EXT duty factor for a step-up is:
100% (1 – V
IN
/V
OUT
)
FB Threshold Line Regulation
%/%
REFERENCE AND LDO REGULATORS
OSCILLATOR
PWM CONTROLLER