|  | Ricoh Semiconductor Support Centre launches the RP904 Series PWM/PFM Step Down DCDC Converter with selectable output voltage and bypass mode |
| | Amstelveen, the Netherlands, September 2010 – Ricoh Europe (Netherlands) B.V. Semiconductor Support Centre, has launched the RP904 Step Down DCDC Converter designed to be used in RF power amplifier circuits and targeted to improve transmission power efficiency. |
Ricoh’s semiconductors are dedicated to saving power consumption and are available in very small sized packages, meaning they can be used in a wide variety of small battery-operated wireless devices. The RF transmission power output of wireless devices should depend on the received RF signal strength from a base station. By adjusting the supply voltage of the RF power amplifier circuit, power consumption can be adapted according to the actual need. For instance, if the distance between a portable device and its base station is not far, the device can be set to a reduced transmission power mode. The RP904 has a mode pin to select between two different output voltages and thus makes a selection of two transmission power levels possible. A second mode pin can be used if the battery voltage is low, with this pin disabling and bypassing the Step Down DCDC Converter circuit and connecting the input directly to the output by an internal switch. A third mode pin is used to select a specific operating mode of the DCDC Converter, with a choice of PWM or PFM mode, resulting in the best efficiency level at either low or high output currents.
RP904 is among the smallest solutions for this purpose available on the market, with the chip scaled package occupying only 3.48mm2. This is advantageous when used on high density and small circuit boards. Other factors contributing to circuit board space reduction are the high operating frequency of 2.0MHz resulting in the use of a small sized inductor, and an embedded driver transistor and synchronous rectification, which eliminates the need for an external diode.
In terms of circuit protection, various circuits are embedded, ensuring the safe operation of the power supply. An under voltage lockout function (UVLO) disables the RP904 if the input voltage is below the threshold of the minimum operating voltage, preventing malfunctioning of the internal circuits. An over-current limit circuit limits the Lx peak current at each clock cycle, switching into a latched off-mode if the over-current condition remains for more than 0.8ms. The over-current limit protects the DCDC converter and other electronic parts of the application from damage.
An embedded soft-start function boots the internal circuits in 0.135ms avoiding high inrush current peaks during start-up.
RP904 is available in one package only, the WLCSP-11-P2.
RP904 Features:
| | Input Voltage | 2.5V to 5.5V
2.5V to 5.0V (Vset2 < 1.2V) |
| | Output Voltage Range Vset1: | 1.2V to 3.3V (100mV steps) |
| | Output Voltage Range Vset2: | 1.0V to 1.5V (100mV steps) |
| | Bypass Switch On-Resistance: | Typ. 68mΩ |
| | Oscillator Frequency: | Typ. 2.0MHz |
| | Standby Current: | Typ. 0.02µA |
| | Output Current: | Min. 1000mA |
| | Soft Start Function: | Typ. 0.135ms |
| | UVLO Threshold Voltage: | Typ. 2.25V |
| | Operating Modes: | PWM or PFM mode controlled by a mode pin |
| | Current Limit Protection Circuit: | Latched Type, delay Typ. 0.8ms |
| | Input / Output Capacitor: | Ceramic, Min. 4.7µF / Min. 10µF |
| | Inductor: | 2.2µH |
| | Package RP904Z: | (L2.37 x W1.47 x H0.78mm) WLCSP-11-P2 |
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About Ricoh
Ricoh Company, Ltd (“Ricoh Company”) is a global technology leader, specialising in the office and production printing markets. Ricoh works with organisations around the world to modernise work environments and optimise document efficiency.
With over 108,500 employees worldwide, it operates in Europe, the Americas, Asia Pacific, China and Japan. Ricoh Europe Holdings Plc is a public limited company and the EMEA headquarters of Ricoh Company with operations located in London, United Kingdom and Amstelveen, the Netherlands. In the fiscal year ended 31 March 2010, revenues from Ricoh's EMEA operations totalled over YEN 458.5 billion ($4.5bn) Ricoh Company's worldwide sales totalled over YEN 2,016 billion ($21bn) during the year ended 31 March 2010. For further information please contact:
Ricoh Europe (Netherlands) B.V.
Semiconductor Support Centre
Manager: Hans Adams
Tel: +31 (0)20 54 74 309
Fax: +31 (0)20 54 74 791
E-mail:semicon@ricoh-europe.com
Homepage: www.ricoh.com/LSI/ | |
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