Datasheet

MAX8655
Highly Integrated, 25A, Wide-Input,
Internal MOSFET, Step-Down Regulator
4 _______________________________________________________________________________________
ELECTRICAL CHARACTERISTICS (continued)
(V
IN
= 12V, V
BST
- V
LX
= 6.5V, T
A
= -40°C to +85°C, circuit of Figure 4, typical values are at T
A
= +25°C, unless otherwise noted.) (Note 2)
PARAMETER CONDITIONS MIN TYP MAX UNITS
OSCILLATOR
R
FSYNC
= 21.0kΩ 800 1000 1200
Switching Frequency
R
FSYNC
= 143kΩ 160 200 240
kHz
Minimum Off-Time Measured at LX 235 ns
Minimum On-Time Measured at LX 75 100 ns
FSYNC Synchronization Range 160 1200 kHz
FSYNC Input High Pulse Width 100 ns
FSYNC Input Low Pulse Width 100 ns
FSYNC Rise/Fall Time 100 ns
SYNCO Phase Shift 180 D eg r ees
SYNCO Output Low Level I
SYNCO
= 5mA 0.4 V
SYNCO Output High Level I
SYNCO
= -5mA V
AV L
- 1V V
FSYNC Input Low 0.4 V
FSYNC Input High 2.5 V
THERMAL PROTECTION
Thermal Shutdown Rising temperature +160 °C
Thermal-Shutdown Hysteresis 15 °C
POK
REFIN = AVL, V
FB
rising, typical hysteresis is 3% 629 650 671 mV
POK Threshold
V R E F IN = 0.75V to 1.5V , V F B r i si ng , typ i cal hyster esi s i s 3% 88.7 91.7 94.7 %
POK Output Voltage, Low V
FB
= 0.6V, I
POK
= 2mA 25 200 mV
POK Leakage Current, High V
POK
= 5.5V
1 µA
OVP
REFIN = AVL 770 800 840 mV
OVP Threshold Voltage
V
REFIN
= 0.7V to 1.5V 110 115 120 %
OVP, Leakage Current, High V
OVP
= 0.8V 500 nA
MODE CONTROL
MODE Logic-Level Low 4.5V ≤ V
AVL
≤ 5.5V 0.4 V
MODE Logic-Level High 4.5V ≤ V
AVL
≤ 5.5V 1.8 V
MODE Input Current V
MODE
= 0 to V
AVL
-1
+1
µA
SHUTDOWN CONTROL
EN Logic-Level Low 4.5V ≤ V
AVL
≤ 5.5V 0.45 V
EN Logic-Level High 4.5V ≤ V
AVL
≤ 5.5V 2 V
V
EN
= 0V -1 +1
EN Input Current
V
EN
= 28V 1.5 6.0
µA
Note 2: Specifications are 100% production tested at T
A
= +85°C. Limits over the operating temperature range are guaranteed by
design.