Electrical characteristics – Rainbow Electronics MAX1865 User Manual
Page 4
MAX1864/MAX1865
xDSL/Cable Modem Triple/Quintuple Output
Power Supplies
4
_______________________________________________________________________________________
PARAMETER
SYMBOL
CONDITIONS
MIN
MAX
UNITS
GENERAL
Operating Input Voltage Range
(Note 1)
V
IN
4.5
28
V
MAX1864
2
Quiescent Supply Current
I
IN
V
FB
= 0, V
OUT
= 4V, V
FB2
= V
FB3
= V
FB4
= 1.5V,
V
FB5
= -0.1V
MAX1865
3
mA
VL REGULATOR
Output Voltage
VL
6V < V
IN
< 28V, 0.1mA < I
LOAD
<20mA
4.75
5.25
V
Power-Supply Rejection
PSRR
V
IN
= 6V to 28V
3
%
Undervoltage Lockout Trip Level
V
UVLO
VL rising, 3% hysteresis (typ)
3
4
V
DC-DC CONTROLLER
Output Voltage (Preset Mode)
V
OUT
FB = GND
3.247
3.380
V
Feedback Set Voltage
(Adjustable Mode)
V
SET
FB = COMP
1.211
1.261
V
Current-Sense Amplifier Voltage
Gain
A
LIM
V
IN
- V
LX
= 250mV
4.12
5.68
V/V
Current-Limit Threshold
(Internal Mode)
V
VALLEY
V
ILIM
= 5V
150
350
mV
Current-Limit Threshold
(External Mode)
V
VALLEY
V
ILIM
= 2.5V
400
660
mV
MAX186_T
160
240
Switching Frequency
f
OSC
MAX186_U
80
120
kHz
Maximum Duty Cycle
D
MAX
74
90
%
POSITIVE ANALOG GAIN BLOCKS
FB2, FB3, FB4 Regulation
Voltage
V
B2
= V
B3
= V
B4
= 5V, I
B2
= I
B3
= I
B4
=
1mA (sink)
1.215
1.265
V
FB2, FB3, FB4 to B_
Transconductance
∆V
FB
_
V
B2
= V
B3
= V
B4
= 5V, I
B2
= I
B3
= I
B4
=
0.5mA to 5mA (sink)
-2.25
%
NEGATIVE ANALOG GAIN BLOCK
FB5 Regulation Voltage
V
B5
= V
OUT
- 2V, V
OUT
= 3.5V, I
B5
= 1mA
(source)
-25
+10
mV
FB5 to B5 Transconductance
∆V
FB5
V
B5
= 0, I
B5
= 0.5mA to 5mA (source)
-30
mV
ELECTRICAL CHARACTERISTICS
(V
IN
= 12V, ILIM = FB = GND, V
BST
- V
LX
= 5V, T
A
= -40°C to +85°C, unless otherwise noted.) (Note 4)