MAX1864 Maxim, MAX1864 Datasheet

no-image

MAX1864

Manufacturer Part Number
MAX1864
Description
xDSL/Cable Modem Triple/Quintuple Output Power Supplies
Manufacturer
Maxim
Datasheet

Available stocks

Company
Part Number
Manufacturer
Quantity
Price
Part Number:
MAX1864EEE
Manufacturer:
MAXIM/美信
Quantity:
20 000
Part Number:
MAX1864TEEE
Manufacturer:
MAXIM
Quantity:
81
Part Number:
MAX1864TEEE
Manufacturer:
MAXIM/美信
Quantity:
20 000
Part Number:
MAX1864TEEE+
Quantity:
231
Part Number:
MAX1864TEEE-T
Manufacturer:
ANPEC
Quantity:
3 400
The MAX1864/MAX1865 power-supply controllers are
designed to address cost-conscious applications such
as cable modem Consumer Premise Equipment (CPE),
xDSL CPE, and set-top boxes. Operating off a low-cost,
unregulated DC supply (such as a wall adapter output),
the MAX1864 generates three positive outputs, and the
MAX1865 generates four positive outputs and one neg-
ative output to provide a cost-effective system power
supply.
The MAX1864 includes a current-mode synchronous
step-down controller and two positive regulator gain
blocks. The MAX1865 has one additional positive gain
block and one negative regulator gain block. The main
synchronous step-down controller generates a
high-current output that is preset to 3.3V or adjustable
from 1.236V to 0.8
divider. The 100kHz/200kHz operating frequency
allows the use of low-cost aluminum-electrolytic capaci-
tors and low-cost power magnetics. Additionally, the
MAX1864/MAX1865 step-down controllers sense the
voltage across the low-side MOSFET’s on-resistance to
efficiently provide the current-limit signal, eliminating
the need for costly current-sense resistors.
The MAX1864/MAX1865 generate additional supply
rails at low cost. The positive regulator gain blocks use
an external PNP pass transistor to generate low-voltage
rails directly from the main step-down converter (such
as 2.5V or 1.8V from the main 3.3V output) or higher
voltages using coupled windings from the step-down
converter (such as 5V, 12V, or 15V). The MAX1865’s
negative gain block uses an external NPN pass transis-
tor in conjunction with a coupled winding to generate
-5V, -12V, or -15V.
All output voltages are externally adjustable, providing
maximum flexibility. Additionally, the MAX1864/
MAX1865 feature soft-start for the step-down converter
and all the positive linear regulators, and have a power-
good output that monitors all of the output voltages.
19-2030; Rev 0; 4/01
For pricing, delivery, and ordering information, please contact Maxim/Dallas Direct! at
1-888-629-4642, or visit Maxim’s website at www.maxim-ic.com.
xDSL, Cable, and ISDN Modems
Set-Top Boxes
Wireless Local Loop
xDSL/Cable Modem Triple/Quintuple Output
________________________________________________________________ Maxim Integrated Products
V
General Description
IN
with an external resistive-
Applications
o 4.5V to 28V Input Voltage Range
o Master DC-DC Step-Down Converter
o Two (MAX1864)/Four (MAX1865) Analog
o Power-Good Indicator
o Soft-Start Ramp for All Positive Regulators
MAX1864TEEE
MAX1864UEEE
MAX1865TEEP
MAX1865UEEP
Gain Blocks
Pin Configurations continued at end of data sheet.
Preset 3.3V or Adjustable (1.236V to 0.8 ✕ V
Output Voltage
Fixed-Frequency (100kHz/200kHz) PWM
Controller
No Current-Sense Resistor
Adjustable Current Limit
95% Efficient
Positive Analog Blocks Drive Low-Cost PNP
Pass Transistors to Build Positive Linear
Regulators
Negative Analog Block (MAX1865) Drives a
Low-Cost NPN Pass Transistor to Build a
Negative Linear Regulator
TOP VIEW
PART
COMP
POK
OUT
FB2
FB3
FB
B2
B3
Power Supplies
-40°C to +85°C
-40°C to +85°C
-40°C to +85°C
-40°C to +85°C
1
2
3
4
5
6
7
8
RANGE
Ordering Information
TEMP.
16 QSOP
MAX1864
Pin Configurations
PIN-
PACKAGE
16 QSOP
16 QSOP
20 QSOP
20 QSOP
16
15
14
13
12
11
10
9
IN
VL
BST
DH
LX
DL
GND
ILIM
Features
(kHz)
f
200
100
200
100
OSC
IN
)
1

Related parts for MAX1864

Related keywords