Datasheet

MAX16955
36V, 1MHz Step-Down Controller
with Low Operating Current
3
Maxim Integrated
PARAMETER SYMBOL CONDITIONS MIN TYP MAX UNITS
FB Line Regulation V
EN
= V
SUP
, 6V < V
SUP
< 36V (Note 4) 0.02 %/V
Transconductance (from FB to
COMP)
g
m,EA
1200 μS
Error-Amplifier Output
Impedance
R
OUT,EA
30 M
R
FOSC
= 76.8k 360 400 440
Operating Frequency f
SW
R
FOSC
= 30.1k 1000
kHz
Minimum On-Time t
ON(MIN)
80 ns
Maximum FSYNC Frequency f
FSYNC(MAX)
1100 kHz
Minimum FSYNC Frequency f
FSYNC(MIN)
f
FSYNC
> 110% of internal frequency (20%
duty cycle), f
SW
= 220kHz
242 kHz
FSYNC Switching Threshold
High
V
FSYNC,HI
1.4 V
FSYNC Switching Threshold Low V
FSYNC,LO
0.4 V
FSYNC Internal Pulldown
Resistance
1 M
CURRENT LIMIT
CS Input Current I
CS
V
CS
= V
OUT
= 0V or V
BIAS
(Note 4) -1 +1 μA
During normal operation 22
Output Input Current I
OUT
V
FB
= V
BIAS
32
μA
CS Current-Limit Voltage
Threshold
V
LIMIT
V
CS
- V
OUT
, V
BIAS
= 5V, V
OUT
 2.5V 68 80 92 mV
FAULT DETECTION
Output Overvoltage Trip
Threshold
V
FB,OV
V
OUT
= V
FB
, rising edge 108 113 118 %V
FB
Output Overvoltage Trip
Hysteresis
2.5 %
Rising edge 25
Output Overvoltage Fault
Propagation Delay
t
OVP
Falling edge 25
μs
Output Undervoltage Trip
Threshold
V
FB,UV
V
OUT
= V
FB
; with respect to slewed FB
threshold, falling edge
83 88 93 %V
FB
Output Undervoltage Trip
Hysteresis
2.5 %
Falling edge 25
Output Undervoltage
Propagation Delay
Rising edge (excluding startup) 25
μs
PGOOD Output Low Voltage V
PGOOD,L
I
SINK
= 3mA 0.4 V
PGOOD Leakage Current I
PGOOD
1 μA
Thermal Shutdown Threshold T
SHDN
(Note 5) +175 °C
Thermal Shutdown Hysteresis (Note 5) 15 °C
ELECTRICAL CHARACTERISTICS (continued)
(V
SUP
= V
EN
= 14V, C
IN
= 10μF, C
OUT
= 94μF, C
BIAS
= 2.2μF, C
BST
= 0.1μF, R
FOSC
= 76.8kΩ, T
A
= T
J
= -40°C to +125°C, unless
otherwise noted. Typical values are at T
A
= +25°C.) (Note 2)