Datasheet

TL284x, TL384x
CURRENT-MODE PWM CONTROLLERS
SLVS038G − JANUARY 1989 − REVISED FEBRUARY 2008
6
POST OFFICE BOX 655303 • DALLAS, TEXAS 75265
electrical characteristics over recommended operating free-air temperature range, V
CC
= 15 V (see
Note 4), R
T
= 10 kΩ, C
T
= 3.3 nF (unless otherwise specified) (continued)
current-sense section
PARAMETER
TEST CONDITIONS
TL284x TL384x
UNIT
PARAMETER TEST CONDITIONS
MIN TYP
†
MAX MIN TYP
†
MAX
UNIT
Voltage amplification See Notes 6 and 7 2.85 3 3.13 2.85 3 3.15 V/V
Current-sense comparator threshold COMP at 5 V, See Note 6 0.9 1 1.1 0.9 1 1.1 V
Supply-voltage rejection ratio V
CC
= 12 V to 25 V, See Note 6 70 70 dB
Input bias current −2 −10 −2 −10 µA
Delay time to output 150 300 150 300 ns
†
All typical values are at T
A
= 25°C.
NOTES: 4. Adjust V
CC
above the start threshold before setting it to 15 V.
6. These parameters are measured at the trip point of the latch, with VFB at 0 V.
7. Voltage amplification is measured between ISENSE and COMP, with the input changing from 0 V to 0.8 V.
output section
PARAMETER
TEST CONDITIONS
TL284x TL384x
UNIT
PARAMETER TEST CONDITIONS
MIN TYP
†
MAX MIN TYP
†
MAX
UNIT
High level output voltage
I
OH
= −20 mA 13 13.5 13 13.5
V
High-level output voltage
I
OH
= −200 mA 12 13.5 12 13.5
V
Low level output voltage
I
OL
= 20 mA 0.1 0.4 0.1 0.4
V
Low-level output voltage
I
OL
= 200 mA 1.5 2.2 1.5 2.2
V
Rise time C
L
= 1 nF, T
A
= 25°C 50 150 50 150 ns
Fall time C
L
= 1 nF, T
A
= 25°C 50 150 50 150 ns
†
All typical values are at T
A
= 25°C.
NOTE 4: Adjust V
CC
above the start threshold before setting it to 15 V.
undervoltage-lockout section
PARAMETER
TL284x TL384x
UNIT
PARAMETER
MIN TYP
†
MAX MIN TYP
†
MAX
UNIT
Start threshold voltage
TLx842, TLx844 15 16 17 14.5 16 17.5
V
Start threshold voltage
TLx843, TLx845 7.8 8.4 9 7.8 8.4 9
V
Minimum operating voltage after startup
TLx842, TLx844 9 10 11 8.5 10 11.5
V
Minimum operating voltage after startup
TLx843, TLx845 7 7.6 8.2 7 7.6 8.2
V
†
All typical values are at T
A
= 25°C.
NOTE 4: Adjust V
CC
above the start threshold before setting it to 15 V.
pulse-width-modulator section
PARAMETER
TL284x TL384x
UNIT
PARAMETER
MIN TYP
†
MAX MIN TYP
†
MAX
UNIT
Maximum duty cycle
TLx842, TLx843 95 97 100 95 97 100
Maximum duty cycle
TLx844, TLx845 46 48 50 46 48 50
%
Minimum duty cycle 0 0
†
All typical values are at T
A
= 25°C.
NOTE 4: Adjust V
CC
above the start threshold before setting it to 15 V.