SOURCE: Intersil

January 02, 2007 06:00 ET

Intersil's LDO Provides Stable Power for GSM-Based Cell Phone Applications

Intersil's ISL9003A Delivers PSRR of 90dB at 1kHz and Output Noise of 20uVRMS in a Tiny 1.6x1.6 uTDFN Package

MILPITAS, CA -- (MARKET WIRE) -- January 2, 2007 -- Intersil Corporation (NASDAQ: ISIL), a world leader in the design and manufacture of high-performance analog semiconductors, today introduced the ISL900 3ALDO (low dropout) regulator. This device combines superior PSRR (power supply rejection ratio) for stability and low noise for integration, making it ideally suited for GSM (global system for mobile) portable wireless applications.

In GSM cell phones, the RF PA switches on and off at a rate of 217Hz. During the on state, the RF PA sends data to the base station and the off state allows the phone to conserve battery power. During this on/off state the cell phone battery can drop as low as 500mV from its nominal voltage. The ISL9003A with a PSRR of 90dB is immune to these wide voltage drops, providing a very stable output voltage rail and continuous 150mA of load current.

The ISL9003A, with an output noise of just 20uVRMS, also provides a discrete solution that enables integration of several modules or functions into a cell phone. This low noise, along with the PSRR, allows this device to be interfaced with an RX transceiver module or a camera module in a cell phone, as applications like this require a high level of performance that is not often achieved in integrated PMIC solutions.

"The ISL9003A provides outstanding low noise and low quiescent current and ripple rejection, critical for handheld and cell phone applications. All of these features are housed in a very tiny package solution of 1.6x1.6mm uTDFN," said Andrew Rhind, vice president and general manager of Intersil's Consumer Power products group. "High performance is achieved through a circuit that delivers fast transient response to varying load conditions, and in a quiescent condition the ISL9003A adjusts its biasing to achieve the lowest possible standby current consumption. This is an incredibly high-performing part that gives customers the extra level of performance required for handheld and cell phone applications."

High Performance and Low Power Consumption

The ISL9003A has a no-load quiescent current of 30uA (typical) and 0.5uA shutdown current and is stable with 1uF of MLCC output capacitance with an ESR of up to 200 Ohms. It comes in many fixed voltage options with +/-1.8% output voltage accuracy over temperature, line and load. Other output voltage options are available on request.

Key Features

--  High-performance LDO with 150mA continuous output
--  Excellent transient response to large current steps
--  Excellent load regulation: < 0.1% voltage change across full range of
    load current
--  Very high PSRR: > 90dB @ 1kHz
--  Wide input voltage capability: 2.3V - 6.5V
--  Extremely low quiescent current: 30uA
--  Low dropout voltage: typically 200mV @ 150mA
--  Low output noise: typically 20uVRMS @ 100uA (1.5V)
--  Stable with 1uF-4.7uF ceramic capacitors
--  Shutdown pin turns off LDO with 1uA (max) standby current
--  Soft-start limits input current surge during enable
--  Current limit and overheat protection
--  +/-1.8% accuracy over all operating conditions
--  5 Ld SC-70, and 1.6x1.6mm uTDFN package solutions
--  -40 degrees C to +85 degrees C operating temperature range
--  Pb-free plus anneal available (RoHS compliant)
Target Applications
--  PDAs, cell phones and smart phones
--  Portable instruments, MP3 players
--  Handheld devices including medical handhelds
About Intersil's Power Management Portfolio

Intersil's high-performance analog ICs provide innovative power management solutions for applications in the computing, communications, peripherals, display, networking, telecommunications, industrial, instrumentation and battery-powered products markets. Intersil is a leading supplier of PWM controller ICs with over two billion units shipped. Intersil offers a broad portfolio of power management ICs, including single and multiple output switching regulators, integrated FET DC/DC controllers, battery management ICs, hot plug controllers and power MOSFET drivers. To learn more, visit Intersil's Power Management page at

Pricing and Availability

The ISL9003A is available now in a 5-lead SC-70 package and is priced at $1.27 in 1,000-unit quantities. For more information on the ISL9003A, visit,1477,ISL9003A,0.html.

A large selection of power products is supported by Intersil's iSim™ online design tool. To explore these solutions, visit

Note to editors: To view a high-resolution downloadable photo of the ISL9003A, visit Intersil's photo room at:

About Intersil

Intersil Corporation is a leader in the design and manufacture of high-performance analog semiconductors. The Company's products address some of the industry's fastest growing markets such as flat panel displays, cell phones, handheld products and notebook computing. Intersil's product families address both power management and analog signal processing functions. Intersil products include ICs for battery management; hot-swap and hot-plug controllers; linear regulators; supervisory ICs; switching DC/DC regulators; power MOSFET drivers; optical storage laser diode drivers; DSL line drivers; video and high-performance operational amplifiers; data converters; interface ICs; analog switches and multiplexers; crosspoint switches; voice-over-IP devices; and ICs for military, space and radiation-hardened applications. For more information about Intersil or to find out how to become a member of our winning team, visit the Company's web site and career page at

FlexiHash and iSim are trademarks of Intersil Americas, Inc. All other brands or product names are trademarks or registered trademarks of their respective holders.

Contact Information

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    Kim Fehrt
    Public Relations Manager
    Intersil Corporation
    (408) 546-3566
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