Ultra-Compact (MSOP8) Automotive-Grade SPI Bus EEPROMs


ROHM Co., Ltd. has recently announced the development of the BR35Hxxx series of SPI bus EEPROMs optimized for various on-board ECUs, such as ABS, automatic transmission, and airbags. A high degree of reliability has been achieved in an ultra-compact package, with operation guaranteed up to 125ºC.

The integration of electronics in cars has shown a marked increase in recent years. Today's vehicles now feature multiple ECUs in a variety of systems. Technological advancements have resulted in more sophisticated control, increasing the amount of information required. As a result, the scale of electronic circuits has expanded dramatically, along with the number of EEPROMs used, primarily for malfunction diagnosis and recording status information. The increased board density required due to the proliferation of electronics demands faster, higher capacity EEPROMs in a smaller form factor.

In response to this, ROHM offers the BR35Hxxx series of SPI bus EEPROMs in the compact MSOP8 package, featuring a chip area 60% smaller than conventional standard products (SOP8). This new series features a number of advantages over conventional products in order to meet the various demands of today's sophisticated systems,
①a unique double cell structure that eliminates accidental malfunctions caused by incidental devices degradation,
②a built-in double reset circuit that prevents erroneous writing, even during unstable battery supply, and
③an ESD resistance of 6kV (HBM), ensuring high strength against electrostatic surge voltages.
A broad lineup is available in a wide range of capacities, interfaces, and package types.

Availability : Now (Samples), June 2010 (OEM quantities)
Pricing : 500yen (16kbit), 600yen (128kbit)

Key Features

  • Compact MSOP8 package (4.0mm×2.9mm) offered (16Kbit and 32Kbit)
  • Available in a number of different capacities (128Kbit max)
  • Stable operation up to 125ºC
  • Eliminates write-protect and hold functions (terminals), shortening the design and evaluation periods
  • Double cell structure prevents accidental malfunctions/failures
  • Integrated double reset function protects against data Write errors

Package Comparison

Package Comparison

Electrical Characteristics

Part No. No.of Data
Years of
Data Output
Delay Time
Data Write
BR35Hxxx Series 1000,000 times
(at 85ºC)
300,000 times
(at 125ºC)
40 years
(at 25ºC)
20 years
(at 125ºC)
1.5mA 10µA 5MHz 70ns 5ms

*1 BR35H128

Operating Range

Supply Voltage: 2.5V to 5.5V, Operating Temperature: −40ºC to +125ºC

Package Lineup

Part No. Capacity Bit
Package Type
(Size: L x W x H) (mm)
BR35Hxxx series 16Kbit 2K×8 BR35H160F-WC BR35H160FJ-WC BR35H160FVT-WC BR35H160FVM-WC
32Kbit 4K×8 BR35H320F-WC BR35H320FJ-WC BR35H320FVT-WC BR35H320FVM-WC
128Kbit 16K×8 BR35H128F-WC BR35H128FJ-WC - -


  • EEPROM (Electrically Erasable Programmable Read Only Memory)
    Memory that stores data even without power. Data can be erased and re-written via an external source.
  • ECU (Electronic Control Unit)
    An electronic circuit that controls system functions (i.e. engine, brakes, airbags) based on data received from various sensors.
  • Double Cell
    ROHM's unique memory configuration whereby 2 memory cells are connected together to store a single unit of data in an "OR" condition. Should one cell malfunction the other will automatically begin to operate, providing seamless operation. This failsafe countermeasure dramatically reduces accidental malfunctions. All of ROHM's EEPROMs feature this double cell structure.
  • Double Reset Function
    The internal circuitry of ICs becomes extremely unstable when power is turned ON or OFF. ROHM EEPROMs utilize 2 circuits - a power ON reset circuit and an undervoltage malfunction prevention circuit – that detect low voltage states during power outages or when power is turned ON or OFF, preventing malfunctions due to unstable conditions.
  • SPI Bus
    A serial interface developed by Motorola consisting of 4 signal lines in order to reduce the number of wires. Often used for flash memory connections.
  • HBM Method
    HBM, short for Human Body Model, is an ESD test method mimicking the amount of static electricity discharged from an electrically charged human body.