Rainbow Electronics MAX799 User Manual

Page 11

MAX796/MAX797/MAX799

Step-Down Controllers with

Synchronous Rectifier for CPU Power

______________________________________________________________________________________

Table 1. Component Selection for Standard 3.3V Applications

Table 2. Component Suppliers

Distributor

losses due to MOSFET gate charge. The 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 of the AC voltage at the
switching node, which is adjusted and 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 circuit that uses a 100nF capaci-
tor connected to BST.

The MAX796 contains nine major circuit blocks, which
are shown in Figure 2.

[1] 714-960-6492

(714) 969-2491

Matsuo

[1] 512-992-3377

(512) 992-7900

IRC

[1] 310-322-3332

(310) 322-3331

International Rectifier

[1] 605-665-1627

(605) 668-4131

Dale

[1] 561-241-9339

(561) 241-7876

Coiltronics

[1] 847-639-1469

(847) 639-6400

Coilcraft

[1] 516-435-1824

(516) 435-1110

Central Semiconductor

[1] 803-626-3123

(803) 946-0690

AVX

FACTORY FAX

[Country Code]

USA PHONE

MANUFACTURER

[1] 864-963-6521

(864) 963-6300

Kemet

1.5µH, 11A, 3.5m

Ω

Coiltronics
CTX03-12357-1

4.7µH, 5.5A Ferrite
Coilcraft DO3316-472

10µH, 3A Ferrite
Sumida CDRH125

33µH, 2.2A Ferrite
Dale LPE6562-330MB

47µH, 1.2A Ferrite or
Kool-Mu
Sumida CD75-470

L1 Inductor

3 x 0.02

Ω

IRC

LR2010-01-R020
(3 in parallel)

0.015

Ω

IRC

LR2010-01-015

0.025

Ω

IRC

LR2010-01-R025

0.039

Ω

IRC

LR2010-01-R039

0.062

Ω

IRC

LR2010-01-R062

R1 Resistor

1N5820 NIEC
NSQ03A02, or
Motorola MBRS340T3

1N5821 NIEC
NSQ03A04 or
Motorola MBRS340T3

1N5819 NIEC
EC10QS03 or
Motorola MBRS130T3

1N5817 NIEC
EC10QS02L or
Motorola MBRS130T3

1N5817 Motorola
MBR0502L SOD-89

D1 Rectifier

4 x 220µF, 10V
Sanyo OS-CON
10SA220M

3 x 220µF, 10V AVX
TPS or Sprague 595D

220µF, 10V AVX TPS
or Sprague 595D

150µF, 10V AVX TPS
or Sprague 595D

C2 Output
Capacitor

2 x 220µF, 10V
Sanyo OS-CON
10SA220M

4 x 22µF, 35V AVX
TPS or Sprague 595D

2 x 22µF, 35V AVX
TPS or Sprague 595D

22µF, 35V AVX TPS
or Sprague 595D

C1 Input
Capacitor

Motorola
MTD75N03HDL
D

PAK

Motorola
MTD20N03HDL
DPAK

Motorola
MMSF5N03HD or
Si9410

Motorola 1/2
MMDF3N03HD or 1/2
Si9936

International Rectifier
1/2 IRF7101

Q2 Low-Side
MOSFET

Motorola
MTD75N03HDL
D

PAK

Motorola
MTD20N03HDL
DPAK

Motorola
MMSF5N03HD or
Si9410

Motorola 1/2
MMDF3N03HD or 1/2
Si9936

International Rectifier
1/2 IRF7101

Q1 High-Side
MOSFET

4.5V to 6V

4.75V to 24V

4.75V to 28V

4.75V to 18V

Input Range

{1} 847-390-4405

(847) 390-4461

TDK

[81] 3-3607-5144

(847) 956-0666

Sumida

[1] 603-224-1430

(603) 224-1961

Sprague

[1] 408-970-3950

(408) 988-8000
(800) 554-5565

Siliconix

[81] 7-2070-1174

(619) 661-6835

Sanyo

[81] 3-3494-7414

(805) 867-2555*

NIEC

[1] 814-238-0490

(814) 237-1431
(800) 831-9172

Murata-Erie

FACTORY FAX

[Country Code]

USA PHONE

MANUFACTURER

[1] 702-831-3521

(702) 831-0140

Transpower Technologies

[1] 602-994-6430

(602) 303-5454

Motorola

LOAD CURRENT

10A

COMPONENT

300kHz

150kHz

Frequency

Desktop 5V-to-3V

High-End Notebook

Notebook

Sub-Notebook

PDA

Application