MAX1965TEEP Maxim Integrated, MAX1965TEEP Datasheet
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MAX1965TEEP
Manufacturer Part Number
MAX1965TEEP
Description
Current & Power Monitors & Regulators
Manufacturer
Maxim Integrated
Datasheet
1.MAX1965TEEP.pdf
(30 pages)
19-2084; Rev 0; 7/01
The MAX1964/MAX1965 power-supply controllers are
designed to address cost-sensitive applications
demanding voltage sequencing/tracking, 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 MAX1964 generates three positive outputs and the
MAX1965 generates four positive outputs and one neg-
ative output to provide an inexpensive system power
supply.
The MAX1964 includes a current-mode synchronous
step-down controller and two positive regulator gain
blocks. The MAX1965 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 0.75
The 200kHz operating frequency allows the use of low-
cost aluminum-electrolytic capacitors and low-cost
power magnetics. Additionally, the MAX1964/MAX1965
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 cur-
rent-sense resistors.
The MAX1964/MAX1965 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 MAX1965’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. During startup, the MAX1964 fea-
tures voltage sequencing and the MAX1965 features
voltage tracking. Both controllers provide a power-
good output that monitors all of the output voltages.
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.
Typical Operating Circuit appears at end of data sheet.
xDSL, Cable, and ISDN Modems
Set-Top Boxes
Wireless Local Loop
✕
________________________________________________________________ Maxim Integrated Products
V
IN
with an external resistive-divider.
General Description
Tracking/Sequencing Triple/Quintuple
Applications
Power-Supply Controllers
o 4.5V to 28V Input Voltage Range
o Master DC-DC Step-Down Converter:
o Two (MAX1964)/Four (MAX1965) Analog Gain
o Power-Good Indicator
o Voltage Sequencing (MAX1964) or Tracking
MAX1964TEEE
MAX1965TEEP
TOP VIEW
COMP
Blocks:
(MAX1965)
POK
OUT
FB2
FB3
FB
B2
B3
Preset 3.3V or Adjustable (1.236V to 0.75 x V
Output Voltage
Fixed Frequency (200kHz) PWM Controller
No Current-Sense Resistor
Adjustable Current Limit
95% Efficient
Soft-Start
Positive Analog Blocks Drive Low-Cost PNP
Pass Transistors to Build Positive Linear
Regulators
Negative Analog Block (MAX1965) Drives a
Low-Cost NPN Pass Transistor to Build a
Negative Linear Regulator
PA RT
1
2
6
3
4
5
7
8
16-Pin QSOP
MAX1964
-40°C to +85°C
-40°C to +85°C
RANGE
TEMP.
16
15
14
13
12
11
10
9
Ordering Information
IN
VL
BST
DH
LX
DL
GND
ILIM
Pin Configurations
COMP
POK
OUT
FB2
FB3
FB4
FB
B2
B3
B4
10
1
2
3
4
5
6
7
8
9
PIN-
PACKAGE
16 QSOP
20 QSOP
20-Pin QSOP
MAX1965
Features
20
19
18
17
16
15
14
13
12
11
(kHz)
f
200
200
OSC
IN
VL
BST
DH
LX
DL
GND
ILIM
FB5
B5
IN
1
)