U2403B Datasheet, PDF (8/12 Pages) TEMIC Semiconductors – Charge Timer

U2403B
Standard Applications
Basic Example
NiCd battery 750 mAh
Charging time: 3 h
Charge current:
240 mA, 1/3 C
Trickle charge:
19 mA < 1/40 C
W R₁ = 510 , 1/8 W
C₁ = 47 mF/ 16 V
R₃ = 6.2 W, 1/2 W
R₄ = 300 kW
C₄ = 470 pF
R₅ = 8.2 W, 1/2 W
Minimum Supply Voltage
No of Cells
1
2
3
4
5
DC Supply Minimum
6.8 V
8.3 V
9.8 V
11.3 V
12.8 V
Special Requirements of Different Charge
Times
R₄, C₄ values for different charging times
2 h 4 h 6 h 7 h 12 h
R₄ 300 kW 430 kW 470 kW 470 kW 390 kW
C₄ 330 pF 470 pF 680 pF 1 nF 2.2 nF
Basic Equations
R₁ = 0.5 V / I_S
I_S = 1.8 mA
R₅ = V₅/ (I_ch – 20 mA)
Nominal Charge Current:
I_ch = V₃/R₃ where V₃ = 1.48 V (typ.)
Trickle Current:
I_ch = V₃/R₃ + I₈ + I_S
Typical values are:
V₃ = 100 mV, I₈ = 4.5 mA
DC
supply
READY
I_ch
LED₁
8
Charge
R₅
LED₂
R₁
C₁
I_S
7
6
5
U2403B
1
2
3
4
R₄
R₃
C₄
Special Requirements for Different Charge
Current
R₃, R₅ values for different charge current
240 mA 150 mA 100 mA 50 mA
R₃
6.2 W
10 W
15 W
30 W
R₅
8.2 W
15 W
22 W
68 W
Figure 6. Standard application
8 (12)
TELEFUNKEN Semiconductors
Rev. A1, 20-Mar-96