EL7531_06 Datasheet, PDF (1/11 Pages) Intersil Corporation – Monolithic 1A Step-Down Regulator with Low Quiescent Current

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Data Sheet
July 13, 2006
EL7531
FN7428.9
Monolithic 1A Step-Down Regulator with
Low Quiescent Current
The EL7531 is a synchronous, integrated FET 1A step-down
regulator with internal compensation. It operates with an input
voltage range from 2.5V to 5.5V, which accommodates
supplies of 3.3V, 5V, or a Li-Ion battery source. The output can
be externally set from 0.8V to V_IN with a resistive divider.
The EL7531 features automatic PFM/PWM mode control, or
PWM mode only. The PWM frequency is typically 1.4MHz
and can be synchronized up to 12MHz. The typical no load
quiescent current is only 120µA. Additional features include
a Power-Good output, <1µA shut-down current, short-circuit
protection, and over-temperature protection.
The EL7531 is available in the 10 Ld MSOP package,
making the entire converter occupy less than 0.15 in² of
PCB area with components on one side only. The 10 Ld
MSOP package is specified for operation over the full -40°C
to +85°C temperature range.
Ordering Information
PART TAPE &
PART NUMBER MARKING REEL PACKAGE
PKG.
DWG. #
EL7531IY
BEAAA
- 10 Ld MSOP MDP0043
EL7531IY-T7 BEAAA
7” 10 Ld MSOP MDP0043
EL7531IY-T13 BEAAA
13” 10 Ld MSOP MDP0043
EL7531IYZ
(Note)
BHAAA
- 10 Ld MSOP MDP0043
(Pb-free)
EL7531IYZ-T7 BHAAA
(Note)
7” 10 Ld MSOP MDP0043
(Pb-free)
EL7531IYZ-T13 BHAAA
(Note)
13” 10 Ld MSOP MDP0043
(Pb-free)
NOTE: Intersil Pb-free plus anneal products employ special Pb-free
material sets; molding compounds/die attach materials and 100% matte
tin plate termination finish, which are RoHS compliant and compatible
with both SnPb and Pb-free soldering operations. Intersil Pb-free
products are MSL classified at Pb-free peak reflow temperatures that
meet or exceed the Pb-free requirements of IPC/JEDEC J STD-020.
Pinout
EL7531 (10 LD MSOP)
TOP VIEW
1 SGND
FB 10
2 PGND
VO 9
3 LX
PG 8
4 VIN
EN 7
5 VDD SYNC 6
Features
• Less than 0.15 in² (0.97 cm²) footprint for the complete 1A
converter
• Components on one side of PCB
• Max height 1.1mm MSOP10
• Power-Good (PG) output
• Internally-compensated voltage mode controller
• Up to 94% efficiency
• <1µA shut-down current
• 120µA quiescent current
• Overcurrent and over-temperature protection
• External synchronizable up to 12MHz
• Pb-Free plus anneal available (RoHS compliant)
Applications
• PDA and pocket PC computers
• Bar code readers
• Cellular phones
• Portable test equipment
• Li-Ion battery powered devices
• Small form factor (SFP) modules
Typical Application Diagram
EL7531
TOP VIEW
V_S
(2.5V to 5.5V)
L₁
V_O
R₃ 100Ω
C₂
C₃
VIN
VDD
LX _1.8µH
C₁
10µF
10µF
0.1µF
EL7531
R₅ 100kΩ
R₄ 100kΩ
R₆
100kΩ
PG
EN
SYNC
PGND
SGND
R₁*
124kΩ
FB
R₂*
100kΩ
C₄
470pF
VO
(1.8V @ 1A)
* V_O = 0.8V * (1 + R₁ / R₂)
1
CAUTION: These devices are sensitive to electrostatic discharge; follow proper IC Handling Procedures.
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