TC96C55 Datasheet, PDF (7/9 Pages) TelCom Semiconductor, Inc – 3A OUTPUT PROGRAMMABLE POWER OSCILLATOR

3A OUTPUT PROGRAMMABLE
POWER OSCILLATOR
1
TC96C555
TYPICAL CHARACTERISTICS (Cont.)
ROUT vs. Temperature
Output HIGH
10
8
6
5V
4
10V
2 _18V
VIN = 0V
0
–55 –35 –15 5 25 45 65 85 105 125
Temperature (°C)
APPLICATIONS
The oscillator timing can easily be controlled by two
external resistors, R_CHG and R_DIS, and capacitor C. R_CHG
and R_DIS set the two constant current sources for charging
and discharging C. The source current is always flowing
when in operation. When the capacitor has charged to a 2V
threshold, the current sink circuit is enabled to discharge the
ROUT vs. Temperature
Output LOW
7
6
5
4
5V
3
2 ^10V
1 ^18V
VIN = 3V
0
–55 –35 –15 5 25 45 65 85 105 125
Temperature (°C)
2
3
capacitor to the 1V threshold. When 1V is reached, the
4 current sink turns OFF to start another cycle.
Resistor R_CHG is connected from V_REF at Pin 3 to V_R1 Pin
4 to program the charging current. Current is set with resistor
R_DIS connected from V_REF Pin 3 to V_R2 Pin 1. Both currents
can range from 5µA to 150µA.
VDD = 18V
TEST CIRCUIT
INPUT
3
VREF
4
2
1
1µF
0.1µF
WIMA
CERAMIC
8
MKS-2
TC96C555
7
6
OUTPUT
C1 = 1800pF
100KHz Square Wave
tRISE = tFALL ≤ 10nsec
GND
5
+5V
INPUT
0V
18V
OUTPUT
0V
10%
tD1
tF
90%
10%
Figure 1. Output Switching Time
90%
tD2
tR
90%
10%
5
6
3 ^VREF
RCHG
4
VR1
RDIS
2
VIN
C
1
VR2
4V
VREF
1V 2V 3V
ISOURCE
2V
1V
Q3
ISINK
VDD
8
10µF
Q1
7
OUTPUT
6
Q2
5 ^GND
Figure 2. Fixed Frequency Power Oscillator
TELCOM SEMICONDUCTOR, INC.
2V
VIN
1V
VDD
OUTPUT
0V
TCHG
Figure 3. V_IN and Output Waveform
7
8
4-165