Ricoh R1232D – PWM / VFM Step Down DCDC Converter with Synchronous Rectification | Ricoh Europe: copiers, photocopiers, printers, gelsprinters, multifunctional printers

Amstelveen, the Netherlands, March 2006 -- Ricoh Europe B.V., the European headquarters of Ricoh Company Ltd., Tokyo, announces the launch of the R1232D, PWM / VFM step-down DCDC Converter with Synchronous Rectification. A powerful device and space saving solution in a tiny SON8 package, requiring only a few small external components thanks to the built-in driver transistor, synchronous rectification function and high operating frequency.

With only a few external components, the R1232D is a simple, small solution to build a current mode PWM / VFM step-down DCDC converter that has been designed as a power source for portable equipment in general. It operates with maximal 95% efficiency (depending on operating conditions) with only three external components, an inductor and two capacitors. The PWM or VFM operating mode is controlled by a mode pin, PWM mode is preferred to assure high efficiency at high output currents. Alternatively, the system can be switched into the VFM mode to improve efficiency at small load currents.

R1232D Series offers multiple protection circuits such as current limit, which limits peak current of Lx at each clock cycle. Likewise, the Latch Type Protection Circuit is activated when the over-current status function exceeds a certain time in the PWM mode. Latched current limit offers enhanced safety for the application in case a short circuit on the output remains permanent, it prevents overheating of the DCDC Converter or other parts on the circuit board. This condition can be released by using the chip enable circuit or by a restart of the IC.

Furthermore, R1232D incorporates the so-called Under Voltage Lock Out or U.V.L.O. circuit in order to prevent operation under too low input voltage conditions. As for the output voltage setting, one can choose between an adjustable version by using external resistors and an internally fixed version. Also a selection can be made between versions with an oscillator frequency of 1 MHz and 2.25 MHz. R1232D is available in a tiny SON8 package only.

R1232D Features

Operating voltage	Min. 2.6 V to Max. 5.5 V
Supply current	(depending on operating mode and product version) Typ. 45 µA to 240 µA
Standby current	Typ. ~0 µA
Output voltage	(adjustable, C & D version) 0.8 V to Vin, (fixed, A & B version) 0.9 V to 3.3 V
Output current	Min. 1,000 mA
Accuracy	± 2.0%
Operating frequency	(A & C Version) 1 MHz, (B & D Version) 2.25 MHz
Operating mode	(selectable by mode pin) PWM or VFM Mode
Efficiency	(depending on operating conditions) Max. 95%
Protection circuits	Under Voltage Lock Out Latched Current Limit
Other circuits	Soft Start Function
Inductor	(1 MHz ) 4.7 µH, (2.25 MHz) 2.2 µH
Capacitor type	Ceramic
Capacitor	10 µF
Package R1232D	(L 2.9 x W 3.0 x H 0.9 mm) SON8

Ricoh, placed 7th in Fortune’s global computer and office equipment ranking, currently manufactures one of the world's most extensive line ups of copiers, printers, scanners, faxes and multifunctional devices, as well as advanced software solutions. In March 2001, Ricoh established the European Semiconductor Support Centre to support distributors and customers in the field of Power Management and Real Time Clock ICs.