TL284xB, TL384xB
HIGH-PERFORMANCE CURRENT-MODE PWM CONTROLLERS
www.ti.com
FEATURES
•
•
•
•
•
•
•
•
Low Start-Up Current ( 5 kΩ:
f ≈ 1.72 / RTCT
VREF
RT
RT/CT
CT
GND
Figure 3. Oscillator Section
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11
TL284xB, TL384xB
HIGH-PERFORMANCE CURRENT-MODE PWM CONTROLLERS
www.ti.com
SLVS610B – AUGUST 2006 – REVISED JULY 2007
APPLICATION INFORMATION (continued)
TIMING RESISTANCE
vs
FREQUENCY
DEAD TIME
vs
TIMING CAPACITANCE
100
100
CT = 10 nF
VCC = 15 V
RT ≥ 5 kΩ
TA = 25°C
40
CT = 4.7 nF
CT = 2.2 nF
R T − Timing Resistance − k Ω
Dead Time − µ s
40
10
4
1
CT = 1 nF
CT = 22 nF
10
CT = 47 nF
CT = 100 nF
4
0.4
VCC = 15 V
TA = 25°C
1
100
0.1
1
4
10
40
100
1k
10k
100k
1M
f − Frequency − Hz
CT − Timing Capacitance − nF
Open-Loop Laboratory Test Fixture
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-kΩ potentiometer sample the oscillator waveform and apply an
adjustable ramp to the ISENSE terminal.
REF
RT
A
4.7 kΩ
VCC
2N2222
100 kΩ
1-kΩ
Error Amplifier Adjust
VFB
5 kΩ
VREF
COMP
TL284xB
TL384xB
0.1 µF
VCC
0.1 µF
ISENSE
OUTPUT
1 kΩ, 1 W
OUTPUT
4.7 kΩ
ISENSE
Adjust
RT/CT
GND
GND
CT
Figure 4. Open-Loop Laboratory Test Fixture
12
Submit Documentation Feedback
TL284xB, TL384xB
HIGH-PERFORMANCE CURRENT-MODE PWM CONTROLLERS
www.ti.com
SLVS610B – AUGUST 2006 – REVISED JULY 2007
APPLICATION INFORMATION (continued)
Shutdown Technique
The PWM controller (see Figure 5) can be shut down by two methods: either raise the voltage at ISENSE above
1 V or pull the COMP terminal below a voltage two diode drops above ground. Either method causes the output
of the PWM comparator to be high (refer to block diagram). The PWM latch is reset dominant so that the output
remains low until the next clock cycle after the shutdown condition at the COMP or ISENSE terminal is removed.
In one example, an externally latched shutdown can be accomplished by adding an SCR that resets by cycling
VCC below the lower UVLO threshold. At this point, the reference turns off, allowing the SCR to reset.
1 kΩ
VREF
COMP
Shutdown
330 Ω
ISENSE
500 Ω
Shutdown
To Current-Sense
Resistor
Figure 5. Shutdown Techniques
A fraction of the oscillator ramp can be summed resistively with the current-sense signal to provide slope
compensation for converters requiring duty cycles over 50% (see Figure 6). Note that capacitor C forms a filter
with R2 to suppress the leading-edge switch spikes.
VREF
0.1 µF
RT
RT/CT
CT
R1
ISENSE
R2
ISENSE
C
RSENSE
Figure 6. Slope Compensation
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13
PACKAGE OPTION ADDENDUM
www.ti.com
14-Oct-2022
PACKAGING INFORMATION
Orderable Device
Status
(1)
Package Type Package Pins Package
Drawing
Qty
Eco Plan
(2)
Lead finish/
Ball material
MSL Peak Temp
Op Temp (°C)
Device Marking
(3)
Samples
(4/5)
(6)
TL2842BD
ACTIVE
SOIC
D
14
50
RoHS & Green
NIPDAU
Level-1-260C-UNLIM
-40 to 85
TL2842B
Samples
TL2842BD-8
ACTIVE
SOIC
D
8
75
RoHS & Green
NIPDAU
Level-1-260C-UNLIM
-40 to 85
2842B
Samples
TL2842BDR
ACTIVE
SOIC
D
14
2500
RoHS & Green
NIPDAU
Level-1-260C-UNLIM
-40 to 85
TL2842B
Samples
TL2842BDR-8
ACTIVE
SOIC
D
8
2500
RoHS & Green
NIPDAU
Level-1-260C-UNLIM
-40 to 85
2842B
Samples
TL2842BP
ACTIVE
PDIP
P
8
50
RoHS & Green
NIPDAU
N / A for Pkg Type
-40 to 85
TL2842BP
Samples
TL2843BD
ACTIVE
SOIC
D
14
50
RoHS & Green
NIPDAU
Level-1-260C-UNLIM
-40 to 85
TL2843B
Samples
TL2843BD-8
ACTIVE
SOIC
D
8
75
RoHS & Green
NIPDAU
Level-1-260C-UNLIM
-40 to 85
2843B
Samples
TL2843BDR
ACTIVE
SOIC
D
14
2500
RoHS & Green
NIPDAU
Level-1-260C-UNLIM
-40 to 85
TL2843B
Samples
TL2843BDR-8
ACTIVE
SOIC
D
8
2500
RoHS & Green
NIPDAU
Level-1-260C-UNLIM
-40 to 85
2843B
Samples
TL2843BDRG4-8
ACTIVE
SOIC
D
8
2500
RoHS & Green
NIPDAU
Level-1-260C-UNLIM
-40 to 85
2843B
Samples
TL2843BP
ACTIVE
PDIP
P
8
50
RoHS & Green
NIPDAU
N / A for Pkg Type
-40 to 85
TL2843BP
Samples
TL2844BD-8
ACTIVE
SOIC
D
8
75
RoHS & Green
NIPDAU
Level-1-260C-UNLIM
-40 to 85
2844B
Samples
TL2844BDR
ACTIVE
SOIC
D
14
2500
RoHS & Green
NIPDAU
Level-1-260C-UNLIM
-40 to 85
TL2844B
Samples
TL2844BDR-8
ACTIVE
SOIC
D
8
2500
RoHS & Green
NIPDAU
Level-1-260C-UNLIM
-40 to 85
2844B
Samples
TL2844BDRG4-8
ACTIVE
SOIC
D
8
2500
RoHS & Green
NIPDAU
Level-1-260C-UNLIM
-40 to 85
2844B
Samples
TL2845BD
ACTIVE
SOIC
D
14
50
RoHS & Green
NIPDAU
Level-1-260C-UNLIM
-40 to 85
TL2845B
Samples
TL2845BD-8
ACTIVE
SOIC
D
8
75
RoHS & Green
NIPDAU
Level-1-260C-UNLIM
-40 to 85
2845B
Samples
TL2845BDR
ACTIVE
SOIC
D
14
2500
RoHS & Green
NIPDAU
Level-1-260C-UNLIM
-40 to 85
TL2845B
Samples
TL2845BDR-8
ACTIVE
SOIC
D
8
2500
RoHS & Green
NIPDAU
Level-1-260C-UNLIM
-40 to 85
2845B
Samples
TL2845BDRG4-8
ACTIVE
SOIC
D
8
2500
RoHS & Green
NIPDAU
Level-1-260C-UNLIM
-40 to 85
2845B
Samples
Addendum-Page 1
PACKAGE OPTION ADDENDUM
www.ti.com
14-Oct-2022
Orderable Device
Status
(1)
Package Type Package Pins Package
Drawing
Qty
Eco Plan
(2)
Lead finish/
Ball material
MSL Peak Temp
Op Temp (°C)
Device Marking
(3)
Samples
(4/5)
(6)
TL3842BD
ACTIVE
SOIC
D
14
50
RoHS & Green
NIPDAU
Level-1-260C-UNLIM
0 to 70
TL3842B
Samples
TL3842BD-8
ACTIVE
SOIC
D
8
75
RoHS & Green
NIPDAU
Level-1-260C-UNLIM
0 to 70
3842B
Samples
TL3842BDR
ACTIVE
SOIC
D
14
2500
RoHS & Green
NIPDAU
Level-1-260C-UNLIM
0 to 70
TL3842B
Samples
TL3842BDR-8
ACTIVE
SOIC
D
8
2500
RoHS & Green
NIPDAU
Level-1-260C-UNLIM
0 to 70
3842B
Samples
TL3842BP
ACTIVE
PDIP
P
8
50
RoHS & Green
NIPDAU
N / A for Pkg Type
0 to 70
TL3842BP
Samples
TL3843BD
ACTIVE
SOIC
D
14
50
RoHS & Green
NIPDAU
Level-1-260C-UNLIM
0 to 70
TL3843B
Samples
TL3843BD-8
ACTIVE
SOIC
D
8
75
RoHS & Green
NIPDAU
Level-1-260C-UNLIM
0 to 70
3843B
Samples
TL3843BDR
ACTIVE
SOIC
D
14
2500
RoHS & Green
NIPDAU
Level-1-260C-UNLIM
0 to 70
TL3843B
Samples
TL3843BDR-8
ACTIVE
SOIC
D
8
2500
RoHS & Green
NIPDAU
Level-1-260C-UNLIM
0 to 70
3843B
Samples
TL3843BP
ACTIVE
PDIP
P
8
50
RoHS & Green
NIPDAU
N / A for Pkg Type
0 to 70
TL3843BP
Samples
TL3844BD-8
ACTIVE
SOIC
D
8
75
RoHS & Green
NIPDAU
Level-1-260C-UNLIM
0 to 70
3844B
Samples
TL3844BDR
ACTIVE
SOIC
D
14
2500
RoHS & Green
NIPDAU
Level-1-260C-UNLIM
0 to 70
TL3844B
Samples
TL3844BDR-8
ACTIVE
SOIC
D
8
2500
RoHS & Green
NIPDAU
Level-1-260C-UNLIM
0 to 70
3844B
Samples
TL3844BP
ACTIVE
PDIP
P
8
50
RoHS & Green
NIPDAU
N / A for Pkg Type
0 to 70
TL3844BP
Samples
TL3845BD
ACTIVE
SOIC
D
14
50
RoHS & Green
NIPDAU
Level-1-260C-UNLIM
0 to 70
TL3845B
Samples
TL3845BD-8
ACTIVE
SOIC
D
8
75
RoHS & Green
NIPDAU
Level-1-260C-UNLIM
0 to 70
3845B
Samples
TL3845BDR
ACTIVE
SOIC
D
14
2500
RoHS & Green
NIPDAU
Level-1-260C-UNLIM
0 to 70
TL3845B
Samples
TL3845BDR-8
ACTIVE
SOIC
D
8
2500
RoHS & Green
NIPDAU
Level-1-260C-UNLIM
0 to 70
3845B
Samples
TL3845BP
ACTIVE
PDIP
P
8
50
RoHS & Green
NIPDAU
N / A for Pkg Type
0 to 70
TL3845BP
Samples
(1)
The marketing status values are defined as follows:
ACTIVE: Product device recommended for new designs.
LIFEBUY: TI has announced that the device will be discontinued, and a lifetime-buy period is in effect.
Addendum-Page 2
PACKAGE OPTION ADDENDUM
www.ti.com
14-Oct-2022
NRND: Not recommended for new designs. Device is in production to support existing customers, but TI does not recommend using this part in a new design.
PREVIEW: Device has been announced but is not in production. Samples may or may not be available.
OBSOLETE: TI has discontinued the production of the device.
(2)
RoHS: TI defines "RoHS" to mean semiconductor products that are compliant with the current EU RoHS requirements for all 10 RoHS substances, including the requirement that RoHS substance
do not exceed 0.1% by weight in homogeneous materials. Where designed to be soldered at high temperatures, "RoHS" products are suitable for use in specified lead-free processes. TI may
reference these types of products as "Pb-Free".
RoHS Exempt: TI defines "RoHS Exempt" to mean products that contain lead but are compliant with EU RoHS pursuant to a specific EU RoHS exemption.
Green: TI defines "Green" to mean the content of Chlorine (Cl) and Bromine (Br) based flame retardants meet JS709B low halogen requirements of