101-0303 Rabbit Semiconductor, 101-0303 Datasheet - Page 29

• Manufacturer Part Number: 101-0303
• Description: SMARTSCREEN OP7100 DISPLAY
• Manufacturer: Rabbit Semiconductor

Specifications of 101-0303

• Module/board Type: Single Board Computer Module with display
• For Use With/related Products: Single Board Computers
• Lead Free Status / RoHS Status: Vendor undefined / Vendor undefined

Since R34 >> RN2, the difference between V
voltage, would be 5 V × (R30/R34). For a nominal hysteresis voltage of
1.25 V, R
Memory Protection
When
select line, preventing accidental writes.
Battery Backup
The backup battery protects data in the RAM and the real-time clock (RTC).
VRAM, the voltage supplied to the RAM and RTC, can also protect other
devices attached to the system against power failures. The ADM691 super-
visor switches VRAM to VBAT or VCC, whichever is greater. (To prevent
“hunting,” the switchover actually occurs when Vcc is 50 mV higher than
VBAT.)
The circuit draws no current from the battery once regular power is applied.
System Reset
The ADM691 chip drives the
up internally.
OP7100
/RESET
V
V
30
L
H
= 0.25 × R34.
=
Figure 3-3. OP7100 Power-Failure Detection Circuit
=
1
1
is active, the ADM691 supervisor disables the RAM chip-
3 .
3 .
V
V
W
W
⎡
⎢
⎢
⎣
⎡
⎢
⎣
1
1
+
+
⎛
⎜
⎝
⎛
⎜
⎝
R30
R29
R30
R29
/RESET
⎞
⎟
⎠
⎞
⎟
⎠
−
+
⎛
⎜ ⎜
⎝
⎛
⎜
⎝
1.3
R30
R34
R30
line. The
V(R34
⎞
⎟
⎠
5 (
⎤
⎥
⎦
V
-
H
+
1.3
and V
RN2)
/RESET
V)
L
, the hysteresis
⎞
⎟ ⎟
⎠
⎤
⎥
⎥
⎦
W
line is not pulled
RST
Hardware 29
W