Datasheet
MAX8664
Low-Cost, Dual-Output, Step-Down
Controller with Fast Transient Response
_______________________________________________________________________________________ 3
PARAMETER CONDITIONS MIN TYP MAX UNITS
PROTECTION FEATURES
V
FB1
rising 0.75
Overvoltage Protection (OVP)
Threshold
V
FB2
rising, V
REFIN2
≤ 1.3V
REFIN2
+ 0.15
V
V
REFIN2
= V
VCC
, V
FB_
rising, MAX8664B
V
FB1
rising, MAX8664A
0.500 0.525 0.550 V
Power-Good (PWRGD) Threshold
Hysteresis 5 %
T
A
= +85
o
C60
High-Side Current-Sense Program
Current (Note 3)
T
A
= +25
o
C 445060
µA
T
A
= +25°C 0.1 1.0
ILIM Leakage
T
A
= +85°C 0.1
µA
High-Side Current-Sense
Overcurrent Trip Adjustment Range
0.05 0.40 V
Internal Soft-Start Time R
OSC/EN12
= 56.1kΩ, 400kHz 2.5 ms
RE FIN 2 Inter nal P ul l d ow n Resi stance Engaged momentarily at startup 10 20 Ω
Thermal-Shutdown Threshold Junction temperature +160 °C
DRIVER SPECIFICATIONS
V
VL
= 6.5V 1.35 2.1
Sourcing current,
I
DH
= -50mA
V
IN
= V
VL
= V
VCC
= 5V 1.55
V
VL
= 6.5V 0.9 1.4
DH_ Driver Resistance
Sinking current,
I
DH
= 50mA
V
IN
= V
VL
= V
VCC
= 5V 1.0
Ω
V
VL
= 6.5V 1.3 2
Sourcing current,
I
DL
= -50mA
V
IN
= V
VL
= V
VCC
= 5V 1.5
V
VL
= 6.5V 0.6 1.1
DL_ Driver Resistance
Sinking current,
I
DL
= 50mA
V
IN
= V
VL
= V
VCC
= 5V 0.7
Ω
V
VL
= 6.5V 13 25 43
Dead Time for Low-Side to
High-Side Transition
DL_ falling to DH_ rising
V
VL
= 5V 28
ns
DH_ Minimum On-Time 70 108 149 ns
V
BST
- V
LX
= 7V, V
LX
= 28V, V
FB_
= 0.55V 1.25 2.3 mA
BST Current
OSC/EN12 not connected 0.001 µA
Internal Boost Switch Resistance 6 Ω
PWM CLOCK OSCILLATOR
PWM Clock-Frequency Accuracy -15 +15 %
PWM Clock-Frequency Adjustment
Range
R
OSC/EN12
= 226kΩ to 22.6kΩ 100 1000 kHz
OSC/EN12 Disable Current 1.5 2.5 µA
ELECTRICAL CHARACTERISTICS (continued)
(V
IN
= 12V, R
OSC/EN12
to GND = 56.1kΩ, REFIN2 = V
CC
, T
A
= -40°C to +85°C, unless otherwise noted. Typical values are at
T
A
= +25°C.) (Note 2)
Note 2: Specifications at -40°C are guaranteed by design and not production tested.
Note 3: This current linearly compensates for the MOSFET temperature coefficient.