Datasheet

www.ti.com
TIMING RESISTANCE
vs
FREQUENCY
Ω
100 1k 10k 100k 1M
f − Frequency − Hz
R
T
− Timing Resistance − k
100
40
10
4
1
V
CC
= 15 V
T
A
= 25°C
C
T
= 22 nF
C
T
= 47 nF
C
T
= 100 nF
C
T
= 10 nF
C
T
= 4.7 nF
C
T
= 2.2 nF
C
T
= 1 nF
DEAD TIME
vs
TIMING CAPACITANCE
sµ
100401041
C
T
− Timing Capacitance − nF
100
40
10
4
1
0.4
0.1
Dead Time −
V
CC
= 15 V
R
T
≥ 5 kΩ
T
A
= 25°C
Open-Loop Laboratory Test Fixture
2N2222
4.7 kΩ
1-kΩ
Error Amplifier Adjust
4.7 kΩ
5 kΩ
I
SENSE
Adjust
R
T
100 kΩ
V
CC
0.1 µF
0.1 µF
REF
V
CC
OUTPUT
GND
1 kΩ, 1 W
A
C
T
TL284xB
TL384xB
I
SENSE
V
REF
R
T
/C
T
VFB
COMP
OUTPUT
GND
TL284xB , TL384xB
HIGH-PERFORMANCE CURRENT-MODE PWM CONTROLLERS
SLVS610B – AUGUST 2006 – REVISED JULY 2007
APPLICATION INFORMATION (continued)
In the open-loop laboratory test fixture (see Figure 4 ), high peak currents associated with loads necessitate
careful grounding techniques. Timing and bypass capacitors should be connected close to the GND terminal in a
single-point ground. The transistor and 5-k Ω potentiometer sample the oscillator waveform and apply an
adjustable ramp to the I
SENSE
terminal.
Figure 4. Open-Loop Laboratory Test Fixture
12
Submit Documentation Feedback