Electrical characteristics (continued) – Rainbow Electronics MAX1865 User Manual
Page 3
MAX1864/MAX1865
xDSL/Cable Modem Triple/Quintuple Output
Power Supplies
_______________________________________________________________________________________
3
PARAMETER
SYMBOL
CONDITIONS
MIN
TYP
MAX
UNITS
MAX186_T
160
200
240
Switching Frequency
f
OSC
MAX186_U
80
100
120
kHz
Maximum Duty Cycle
D
MAX
77
82
90
%
Soft-Start Period
t
SOFT
1024
1/f
OSC
Soft-Start Steps
V
REF
/64
V
DH Output Low Voltage
I
SINK
= 10mA, measured from DH to LX
0.1
V
DH Output High Voltage
I
SOURCE
= 10mA, measured from BST to DH
0.1
V
DL Output Low Voltage
I
SINK
= 10mA, measured from DL to GND
0.1
V
DL Output High Voltage
I
SOURCE
= 10mA, measured from DL to GND
V
L
- 0.1
V
DH, DL On-Resistance
3
10
Ω
Output Drive Current
Sourcing or sinking, V
DH
or V
DL
= VL/2
0.5
A
LX, BST Leakage Current
V
BST
= V
LX
= V
IN
= 28V, V
FB
= 1.5V
0.03
20
µA
POSITIVE ANALOG GAIN BLOCKS
FB2, FB3, FB4 Regulation
Voltage
V
B2
= V
B3
= V
B4
= 5V,
I
B2
= I
B3
= I
B4
= 1mA (sink)
1.226
1.240
1.257
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)
-1
-1.75
%
Feedback Input Leakage
Current
I
FB
_
V
FB2
= V
FB3
= V
FB4
= 1.5V
0.01
100
nA
V
B2
= V
B3
= V
B4
= 2.5V
10
23
Driver Sink Current
I
B
_
V
FB2
= V
FB3
=
V
FB4
= 1.188V
V
B2
= V
B3
= V
B4
= 4.0V
26
mA
NEGATIVE ANALOG GAIN BLOCK
FB5 Regulation Voltage
V
B5
= V
OUT
- 2V, V
OUT
= 3.5V, I
B5
= 1mA
(source)
-20
-5
+10
mV
FB5 to B5 Transconductance
∆V
FB5
V
B5
= 0, I
B5
= 0.5mA to 5mA (source)
-13
-20
mV
Feedback Input Leakage
Current
I
FB5
V
FB5
= -100mV
0.01
100
nA
Driver Source Current
I
B5
V
FB5
= 200mV, V
B5
= V
OUT
- 2.0V, V
OUT
=
3.5V
10
25
mA
POWER GOOD (POK)
OUT Trip Level (Preset Mode)
FB = GND, falling edge, 1% hysteresis (typ)
2.88
3
3.12
V
FB Trip Level (Adjustable Mode)
Falling edge, 1% hysteresis (typ)
1.070
1.114
1.159
V
FB2, FB3, FB4 Trip Level
Falling edge, 1% hysteresis (typ)
1.070
1.114
1.159
V
FB5 Trip Level
Rising edge, 35mV hysteresis (typ)
368
500
632
mV
POK Output Low Level
I
SINK
= 1mA
0.4
V
POK Output High Leakage
V
POK
= 5V
1
µA
THERMAL PROTECTION (Note 3)
Thermal Shutdown
Rising temperature
160
°C
Thermal Shutdown Hysteresis
15
°C
ELECTRICAL CHARACTERISTICS (continued)
(V
IN
= 12V, ILIM = FB = GND, V
BST
- V
LX
= 5V, T
A
= 0°C to +85°C. Typical values are at T
A
= +25°C, unless otherwise noted.)