HP HP-97 - Page 17

HP-97
driver transistor is turned on, any segment of that digit may light; the
Theory of Operation
segment that lights will now be determined by which anode driver transistor
is switched on. As an example, if all cathode driver transistors were
switched on along with the a-segment anode driver, the a-segment of all
digits across the display would light.
TO ANODE .
DRIVERS
CATHODE
DRIVE —
LINES
CATHODE LINES — KEY
(14 TOTAL) LINES
Figure 2-3. LED Display Format
STR n I-L
SYNC 1 l—_——_l—__
SEGMENTS
A 1 r
B
c— I
D | |
E L
F — l;
G J |
H L
Figure 2-4. SYNC and Display Timing