
MAX8720
Dynamically Adjustable 6-Bit VID
Step-Down Controller
_______________________________________________________________________________________ 5
ELECTRICAL CHARACTERISTICS
(Circuit of Figure 1, V+ =15V, SHDN = SKIP = V
DD
= V
CC
= +5V, V
OUT
= 1.25V, T
A
= -40°C to +85°C, unless otherwise noted.
Typical values are at T
A
= +25°C.) (Note 4)
SYMBOL
MIN TYP MAX
PWM CONTROLLER
Battery Voltage, V+ 2 28
Input Voltage Range
V
CC
, V
DD
4.5 5.5
V
DAC codes from 0.9V
to 1.85V
-1 +1 %
DAC codes from
0.45V to 0.875V
-15
+15
DC Output Voltage Accuracy
V+ = 4.5V to 28V,
includes load
regulation error
DAC codes from
0.275V to 0.425V
-18
+18
115
265 kΩ
150kHz, R
TIME
= 120kΩ -8 +8
818kHz, R
TIME
= 22kΩ -12
+12
TIME Frequency Accuracy
38kHz, R
TIME
= 470kΩ -12
+12
%
V+ = 5V, FB = 1.25V, TON = GND
(1000kHz)
230
165
320
390
On-Time (Note 2) t
ON
V+ = 12V,
FB = 1.25V
TON = V
CC
(200kHz)
465
565
ns
TON = V
CC
, open, or REF (200kHz, 300kHz,
or 550kHz)
500
Minimum Off-Time (Note 2)
t
OFF
MIN
TON = GND (1000kHz) 375
ns
BIAS AND REFERENCE
Quiescent Supply Current (V
CC
)I
CC
FB forced above their regulation points
1300
µA
Quiescent Supply Current (V
DD
)I
DD
FB forced above their regulation points 5 µA
Quiescent Battery Supply
Current (V+)
I
+
40 µA
Shutdown Supply Current (V
CC
)I
CC
SHDN = GND 25 µA
Shutdown Supply Current (V
DD
)I
DD
SHDN = GND 5 µA
Shutdown Battery Supply
Current (V+)
I
+
SHDN = GND, V
CC
= V
DD
= 0V or 5V 5 µA
Reference Voltage V
REF
V
CC
= 4.5V to 5.5V, no REF load
1.98 2.02
V
FAULT DETECTION
V
CC
Undervoltage-Lockout
Threshold
Rising edge, hysteresis = 20mV, PWM
disabled below this level
4.1 4.4 V
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