Low-Noise, 5.5V-Input,
PWM Step-Down Regulator
ELECTRICAL CHARACTERISTICS (continued)
(V
IN
= +3.6V, SYNC/PWM = GND, V
LIM
= 3.6V,
SHDN
= IN, circuit of Figure 2;
T
A
= 0°C to +85°C,
unless otherwise noted. Typical
values are at T
A
= +25°C.)
PARAMETER
Reference Load Regulation
Undervoltage Lockout Threshold
Logic Input High
Logic Input Low
Logic Input Current
SYNC/PWM Minimum Pulse Width
UVLO
V
IH
V
IL
SYMBOL
0
≤
I
REF
≤
50µA
V
IN
rising, typical hysteresis is 85mV
SHDN,
SYNC/PWM, LIM
SHDN,
SYNC/PWM, LIM
SHDN,
SYNC/PWM, LIM
High or low
-1
500
0.1
2.3
2
0.4
1
CONDITIONS
MIN
TYP
3
2.4
MAX
15
2.5
UNITS
mV
V
V
V
µA
ns
MAX1692
ELECTRICAL CHARACTERISTICS
(V
IN
= +3.6V, SYNC/PWM = GND, V
LIM
= 3.6V,
SHDN
= IN, circuit of Figure 2,
T
A
= -40°C to +85°C,
unless otherwise noted.) (Note 3)
PARAMETER
Input Voltage Range
SYMBOL
V
IN
FB = OUT, V
IN
= V
LIM
= 2.7V to 5.5V,
I
OUT
= 0
Output Voltage
V
OUT
FB = OUT, V
IN
= 2.7V to 5.5V,
I
OUT
= 0 to 600mA, LIM = IN or
I
OUT
= 0 to 250mA, LIM = GND
(Note 1)
V
FB
I
FB
FB = OUT, V
IN
= V
LIM
= 5.5V, I
OUT
= 0
(duty cycle = 23%) (Note 2)
V
FB
=1.4V
LIM = GND
LIM = IN
SYNC/PWM = IN, FB = REF
SYNC/PWM = GND, LX = unconnected,
V
FB
= 1.4V
SHDN
= LX = GND, includes LX leakage current
f
OSC
V
REF
UVLO
V
IH
V
IL
I
REF
= 0
V
IN
rising, typical hysteresis is 85mV
SHDN,
SYNC/PWM, LIM
SHDN,
SYNC/PWM, LIM
SHDN,
SYNC/PWM, LIM
-1
630
1.230
2.3
2
0.4
1
CONDITIONS
MIN
2.7
1.213
MAX
5.5
1.285
V
1.185
REF
1.213
-50
0.3
0.7
-15
1.285
V
IN
1.285
50
0.9
1.6
110
140
10
840
1.268
2.5
V
V
nA
A
mA
µA
µA
kHz
V
V
V
V
µA
UNITS
V
Output Adjustment Range
Feedback Voltage
FB Input Current
P-Channel Current-Limit
Threshold
N-Channel Current-Limit
Threshold
Quiescent Current
Shutdown Supply Current
Oscillator Frequency
Reference Output Voltage
Undervoltage Lockout
Threshold
Logic Input High
Logic Input Low
Logic Input Current
Note 1:
Guaranteed by minimum and maximum duty-factor tests.
Note 2:
The following equation can be used to calculate FB accuracy for output voltages other than 1.232V:
(see Feedback Voltage vs. Load Current)
V
FB
= V
FB (NOMINAL)
- (Line Reg) (V
OUT
/ V
IN
- 0.23) / 0.77 - (Load Reg)(I
OUT
+ 0.5
·
I
RIPPLE
) / I
MAX
where: Line Reg = the line regulation
Load Reg = the load regulation
I
RIPPLE
= (1- V
OUT
/ V
IN
)
·
V
OUT
/ (f
OSC
·
L) where L is the inductor value
I
MAX
= 250mA (LIM = GND) or 600mA (LIM = IN)
Note 3:
Specifications to -40°C are guaranteed by design, not production tested.
_______________________________________________________________________________________
3
MAXIM [ MAXIM INTEGRATED PRODUCTS ]
