Th7841a – Rainbow Electronics TH7841A User Manual
Page 8

8
TH7841A
1998A–IMAGE–05/02
Note:
1. Drain supply current I
DD
decreases from 10 mA to 8 mA typically when internal sampling clock is disabled (V
INH
= V
DD
=
15V).
Insertion of a serial resistor (typically 100
Ω) at the driver output avoids spurious negative transients.
Table 6. Selection of Operating Modes
Option
Implementation
Note
No Sampling
Φ
ECHA
(3) and
Φ
ECHB
(25) Connected to VDD
S
Φ
ECHA
(4) and S
Φ
ECHB
(24) Unconnected
V
INH
(16) Connected to V
DD
Sampling By External Clocks
Sampling Clocks Connected to
Φ
ECHA
-
Φ
ECHB
S
Φ
ECHA
and S
Φ
ECHB
Unconnected
V
INH
(16) Connected to V
DD
See Figure 4 for sampling
clock timing
Reset Control By External Clocks
Ext.
Φ
RA
on
Φ
RA
(5) Input
Ext.
Φ
RB
on
Φ
RB
(21) Input
See Figure 4 for
reset clock timing
Table 7. External
ΦRA, ΦRB, ΦECHA, ΦECHB Clocks Characteristics
Parameter
Symbol
Logic
Values
Unit
Min
Typ
Max
External Reset Clock
Sampling Clock
Φ
RA
,
Φ
RB
,
Φ
ECHA
,
Φ
ECHB
High
12
13
14
V
Low
0.0
0.4
0.6
V
Reset And Sampling Clock
Capacitance
C
Φ
RA
C
Φ
RB
C
Φ
ECHA
C
Φ
ECHB
10
15
pF