U2480B Datasheet, PDF (2/8 Pages) TEMIC Semiconductors – Automotive Lamp Outage Monitor

U2480B
Detailed Block Diagram
16
22 V
15
22 V
17
22 V
3
Ref
2
K2
E1
20
Ref
19
E1 K3
21
E2
5
Ref
4
K4
E1
27
Ref
26
K5
E1
1
Ref
28
K6
E1
23
Ref
22
E1 K7
24
E2
7
Ref
8
K8
E1
9
K1
+
–
+
–
I_th
Voltage drift
of comparator
threshold
I_th = f (V_S)
Power-
on
reset
Forward and return counter
T = 1.2 s
Start
High at
forward counter end
Start
return
High at
counter zero
Stabilized
voltage
V_stab= 5.5 V
Oscillator
Divider
Clock 1 Clock 2
T_osc x2 T_osc x20
T1
T2
Set Out
Reset
23 V
7V
7V
T2 T1
Reset
Latch for indicator
and stop lamps
Set ^Out
+
–
Forward and return counter
T = 1.2 s
Start
High at
forward counter end
Start
return
High at
counter zero
+
–
25 V
+
Latched at ^–
signal ”low”
Figure 1. Block diagram
10
V_S
13
V_stab
8
Osc
14
V_out
11
BL
12
SP
13910
2 (8)
TELEFUNKEN Semiconductors
Rev. A1, 22-Oct-97