MAX1901ETJ+ Maxim Integrated Products, MAX1901ETJ+ Datasheet - Page 12

• Manufacturer Part Number: MAX1901ETJ+
• Description: IC CNTRLR PWR SPLY LN 32-TQFN
• Manufacturer: Maxim Integrated Products

Specifications of MAX1901ETJ+

• Applications: Controller, Notebook Computers
• Voltage - Input: 4.2 ~ 30 V
• Number Of Outputs: 4
• Voltage - Output: 2.5 ~ 5 V
• Operating Temperature: 0°C ~ 85°C
• Mounting Type: Surface Mount
• Package / Case: 32-TQFN Exposed Pad
• Output Voltage: 3.3 V, 5 V, 2.5 V to 5.5 V
• Output Current: 5 A
• Input Voltage: 4.2 V to 30 V
• Mounting Style: SMD/SMT
• Maximum Operating Temperature: + 85 C
• Minimum Operating Temperature: - 40 C
• Lead Free Status / RoHS Status: Lead free / RoHS Compliant

The basic MAX1901/MAX1904 dual-output 3.3V/5V
buck converter (Figure 1) is easily adapted to meet a
wide range of applications with inputs up to 28V by
substituting components from Table 1. These circuits
represent a good set of tradeoffs between cost, size,
and efficiency, while staying within the worst-case
specification limits for stress-related parameters, such
as capacitor ripple current. Don’t change the frequency
of these circuits without first recalculating component
values (particularly inductance value at maximum bat-
tery voltage). Adding a Schottky rectifier across each
synchronous rectifier improves the efficiency of these
circuits by approximately 1%, but this rectifier is other-
wise not needed because the MOSFETs required for
these circuits typically incorporate a high-speed silicon
diode from drain to source. Use a Schottky rectifier
rated at a DC current equal to at least one-third of the
load current.
500kHz Multi-Output, Low-Noise Power-Supply
Controllers for Notebook Computers
Table 1. Component Selection for Standard 3.3V/5V Application
12
Input Range
Frequency
Q1, Q3 High-Side
MOSFETs
Q2, Q4 Low-Side
MOSFETs with Integrated
Schottky Diodes
C3 Input Capacitor
C1 Output Capacitor
C2 Output Capacitor
R1, R2 Resistors
L1 Inductor
L2 Inductor
______________________________________________________________________________________
COMPONENT
Standard Application Circuit
7V to 24V
333kHz
1/2 Fairchild FDS6982S or
1/2 International Rectifier
IRF7901D1
1/2 Fairchild FDS6982S or
1/2 International Rectifier
IRF7901D1
3
Taiyo Yuden TMK432BJ106KM
150µF, 6V POSCAP
Sanyo 6TPC150M
2
Sanyo 4TPC150M
0.018Ω
Dale WSL2512-R018-F
10µH, 4.5A Ferrite
Sumida CDRH124-100
7.0µH, 5.2A Ferrite
Sumida CEI122-H-7R0
✕
✕
10µF, 25V ceramic
150µF, 4V POSCAP
4A/333kHz
7V to 24V
500kHz
1/2 Fairchild FDS6982S or
1/2 International Rectifier
IRF7901D1
1/2 Fairchild FDS6982S or
1/2 International Rectifier
IRF7901D1
3
Taiyo Yuden TMK432BJ106KM
150µF, 6V POSCAP
Sanyo 6TPC150M
2
Sanyo 4TPC150M
0.018Ω
Dale WSL2512-R018-F
7.0µH, 5.2A Ferrite
Sumida CEI122-H-7R0
5.6µH, 5.2A Ferrite
Sumida CEI122-H-5R6
✕
✕
The MAX1901/MAX1902/MAX1904 are dual, BiCMOS,
switch-mode power-supply controllers designed pri-
marily for buck-topology regulators in battery-powered
applications where high-efficiency and low-quiescent
supply current are critical. Light-load efficiency is
enhanced by automatic Idle-Mode operation, a vari-
able-frequency pulse-skipping mode that reduces tran-
sition and gate-charge losses. Each step-down,
power-switching circuit consists of two N-channel
MOSFETs, a rectifier, and an LC output filter. The out-
put voltage is the average AC voltage at the switching
node, which is regulated by changing the duty cycle of
the MOSFET switches. The gate-drive signal to the
N-channel high-side MOSFET must exceed the battery
voltage, and is provided by a flying-capacitor boost cir-
cuit that uses a 100nF capacitor connected to BST_.
10µF, 25V ceramic
150µF, 4V POSCAP
LOAD CURRENT
4A/500kHz
Detailed Description
7V to 24V
500kHz
Fairchild FDS6612A or
International Rectifier
IRF7807V
Fairchild FDS6670S or
International Rectifier
IRF7807DV1
4
Taiyo Yuden TMK432BJ106KM
2
Sanyo 6TPC150M
2
Sanyo 4TPC220M
0.012Ω
Dale WSL2512-R012-F
4.2µH, 6.9A Ferrite
Sumida CEI122-H-4R2
4.2µH, 6.9A Ferrite
Sumida CEI122-H-4R2
✕
✕
✕
10µF, 25V ceramic
150µF, 6V POSCAP
220µF, 4V POSCAP
6A/500kHz