AD-PAK® radiation-hardened against natural space radia-
tion
• Total dose hardness:
- > 100 krad (Si), depending upon space mission
• Excellent Single Event Effects:
- No Latchup > 120 MeV/mg/cm
- SEU > 90 MeV/mg/cm
2
2
read mode
• Package:
- 32-pin R
AD-PAK® flat package
- 32-pin Rad-Tolerant flat package
- JEDEC-approved byte-wide pinout
• High speed:
- 120, 150, and 200 ns maximum access times available
• High endurance:
- 10,000 erase/write (in Page Mode),
- 10 year data retention
• Page write mode:
- 1 to 128 bytes
• Low power dissipation
- 20 mW/MHz active (typical)
- 110 µW standby (maximum)
Maxwell Technologies’ 28C011T high-density 1 Megabit (128K
x 8-Bit) EEPROM microcircuit features a greater than 100
krad (Si) total dose tolerance, depending upon space mission.
The 28C011T is capable of i n-system electrical byte and page
programmability. It has a 128-byte page programming function
to make its erase and write operations faster. It also features
data
polling and a Ready/Busy signal to indicate the completion of erase and programming operations. In the 28C010T,
hardware data protection is provided with the RES
tion to noise protection on the WE
signal and write inhibit on
pin, in addi-
power on and off. Software data protection is implemented
using the JEDEC optional standard algorithm.
Maxwell Technologies' patented R
AD-PAK® packaging technol-
ogy incorporates radiation shielding in the microcircuit package. It eliminates the need for box shielding while providing
the required radiation shielding for a lifetime in orbit or space
mission. In a GEO orbit, R
AD-PAK® provides greater than 100
krad (Si) radiation dose tolerance. This product is available
with screening up to Class S.
FIGURE 7. SOFTWARE DATA PROTECTION TIMING WAVEFORM(1) (INPROTECTIONMODE)
IGURE 8. SOFTWARE DATA PROTECTION TIMING WAVEFORM(2) (INNON-PROTECTIONMODE)
F
28C011T
EEPROM APPLICATION NOTES
This application note describes the programming procedures for the EEPROM modules and with details of various
techniques to preserve data protection.
Automatic Page Write
Page-mode write feature allows 1 to 128 bytes of data to be written into the EEPROM in a single write cycle, and
allows the undefined data within 128 bytes to be written corresponding to the undefined address (A0 to A6). Loading
the first byte of data, the data load window opens 30µs for the second byte. In the same manner each additional byte
of data can be loaded within 30µ s. In case CE
erase and write mode automatically and only the input data are written into the EEPROM.
and WE are kept high for 100 µ s after data input, EEPROM enters
11.10.03 REV 10
All data sheets are subject to change without notice
During a write cycle, addresses are latched by the falling edge of WE or CE, and data is latched by the rising edge of
WE
or CE.
Data Polling
Data Polling function allows the status of the EEPROM to be determined. If EEPROM is set to read mode during a
write cycle, an inversion of the last byte of data to be loaded outputs from I/O 7 to indicate that the EEPROM is performing a write operation.
RDY/Busy Signal
RDY/Busy signal also allows a comparison operation to determine the status of the EEPROM. The RDY/Busy signal
has high impedance except in write cycle and is lowered to V
the RDY/Busy
RES Signal
When RES is LOW, the EEPROM cannot be read and programmed. Therefore, data can be protected by keeping
RES
low when VCC is switched. RES should be high during read and programming because it doesn’t provide a latch
function.
signal changes state to high impedance.
after the first write signal. At the-end of a write cycle,
OL
28C011T
Data Protection
To protect the data during operation and power on/off, the EEPROM has the internal functions described below.
1. Data Protection against Noise of Control Pins (CE, OE, WE) during Operation.
11.10.03 REV 10
All data sheets are subject to change without notice
During readout or standby, noise on the control pins may act as a trigger and turn the EEPROM to programming mode by mistake. To prevent this phenomenon, the EEPROM has a noise cancellation function that cuts noise if its width is 20ns or less in
programming mode. Be careful not to allow noise of a width of more than 20ns on the control pins.
28C011T
2. Data Protection at V
When V
programming mode by mistake. To prevent this unintentional programming, the EEPROM must be kept in unprogrammable
state during V
RES
become low, programming operation doesn’t finish correctly in case that RES
should be kept high for 10 ms after the last data input.
is turned on or off, noise on the control pins generated by external circuits, such as CPUs, may turn the EEPROM to
CC
CC
should be kept at VSS level when VCC is turned on or off. The EEPROM breaks off programming operation when RES
on/off
CC
on/off by using a CPU reset signal to RES pin.
falls low during programming operation. RES
3. Software Data Protection
11.10.03 REV 10
All data sheets are subject to change without notice
The software data protection function is to prevent unintentional programming caused by noise generated by external circuits.
In software data protection mode, 3 bytes of data must be input before write data as follows. These bytes can switch the nonprotection mode to the protection mode.
Software data protection mode can be canceled by inputting the following 6 bytes. Then, the EEP ROM turns to the non-pr otection mode and can write data normally. However, when the data is input in the canceling cycle, the data cannot be written.
28C011T
11.10.03 REV 10
All data sheets are subject to change without notice
Important Notice:
These data sheets are created using the chip manufacturers published specifications. Maxwell Technologies verifies
functionality by testing key parameters either by 100% testing, sample testing or characterization.
The specifications presented within these data sheets represent the latest and most accurate information available to
date. However, these specifications are subject to change without notice and Maxwell Technologies assumes no
responsibility for the use of this information.
Maxwell Technologies’ products are not authorized for use as critical components in life support devices or systems
without express written approval from Maxwell Technologies.
Any claim against Maxwell Technologies must be made within 90 days from the date of shipment from Maxwell Technologies. Maxwell Technologies’ liability shall be limited to replacement of defective parts.
28C011T
11.10.03 REV 10
All data sheets are subject to change without notice