AT89C51ED2-SMSIM ATMEL Corporation, AT89C51ED2-SMSIM Datasheet - Page 16

• Manufacturer Part Number: AT89C51ED2-SMSIM
• Description: 8-bit Flash Microcontroller
• Manufacturer: ATMEL Corporation

4.3.4.3 Cell Read Disturb
Purpose:
To measure read disturb influence on 56k8 memory cell.
Test parameters:
Lot:
Programming: 14V on WL and sensegate @5ms
Temperature:
The cell is stressed with BL voltage much higher than standard read conditions (around 6V) to accelerate disturb
phenomenon : electrons from the Floating gate can move through the tunnel oxide. This charge loss is measured
after stress by a Vt measurement.
Test results:
Conclusion:
Extrapolation to 10 years lifetime give a maximum BL voltage of around 4V in read operation, which is much higher
than nominal BL read voltage (~1V). So there is no sensitivity to read disturb either at room temperature or high
temperature.
16
2.5
1.5
0.5
2
1
0
0.1
0t0348
25°C and 140°C
1
0t0348 #01
BL read disturb @25C
10
Time (s)
56.8k (568A6)
100
1000
10000
Vbl=6V
Vbl=6.5V
Vbl=7V
Vbl=7.5V
Vbl=8V
AT89C51RD2 / AT89C51ED2 QualPack
2.5
1.5
0.5
2
1
0
0.1
1
0t0348 #01
BL read disturb @140C
10
Time (s)
56.8k (568A6)
100
1000
10000
Rev. 0 – 2003 July
Vbl=6V
Vbl=6.5V
Vbl=7V
Vbl=7.5V
Vbl=8V