6 Specifications
6.1 Absolute Maximum Ratings(2)(1)
|
MIN |
MAX |
UNIT |
Input supply voltage |
|
45 |
V |
Soft-start pin voltage |
–0.1 |
6 |
V |
Switch voltage to ground(3) |
–1 |
VIN |
V |
Boost pin voltage |
|
VSW + 8 V |
V |
Feedback pin voltage |
–0.3 |
14 |
V |
Power dissipation |
Internally Limited |
|
Soldering temperature |
Wave, 4 s |
|
260 |
°C |
Infrared, 10 s |
|
240 |
Vapor phase, 75 s |
|
219 |
Storage temperature, Tstg |
–65 |
150 |
°C |
(1) If Military/Aerospace specified devices are required, please contact the Texas Instruments Sales Office/Distributors for availability and specifications.
(2) Stresses beyond those listed under Absolute Maximum Ratings may cause permanent damage to the device. These are stress ratings only, which do not imply functional operation of the device at these or any other conditions beyond those indicated under Recommended Operating Conditions. Exposure to absolute-maximum-rated conditions for extended periods may affect device reliability.
(3) The absolute maximum specification of the Switch Voltage to Ground applies to DC voltage. An extended negative voltage limit of –10 V applies to a pulse of up to 20 ns, –6 V of 60 ns and –3 V of up to 100 ns.
6.2 ESD Ratings
|
VALUE |
UNIT |
V(ESD) |
Electrostatic discharge |
Human-body model (HBM), per ANSI/ESDA/JEDEC JS-001(1)(2) |
±2000 |
V |
(1) JEDEC document JEP155 states that 500-V HBM allows safe manufacturing with a standard ESD control process.
(2) ESD was applied using the human-body model, a 100-pF capacitor discharged through a 1.5-kΩ resistor into each pin.
6.3 Recommended Operating Conditions
|
MIN |
MAX |
UNIT |
Supply voltage |
8 |
40 |
V |
Junction temperature (TJ) |
–40 |
125 |
°C |
6.4 Thermal Information
THERMAL METRIC(1) |
LM2678 |
UNIT |
NDZ (TO-220) |
KTW (TO-263) |
NHM (VSON) |
7 PINS |
7 PINS |
14 PINS |
RθJA |
Junction-to-ambient thermal resistance |
See (2) |
65 |
— |
— |
°C/W |
See (3) |
45 |
— |
— |
See (4) |
— |
56 |
— |
See (5) |
— |
35 |
— |
See (6) |
— |
26 |
— |
See (7) |
— |
— |
55 |
See (8) |
— |
— |
29 |
RθJC(top) |
Junction-to-case (top) thermal resistance |
2 |
2 |
— |
°C/W |
(2) Junction to ambient thermal resistance (no external heat sink) for the 7-lead TO-220 package mounted vertically, with ½ inch leads in a socket, or on a PCB with minimum copper area.
(3) Junction to ambient thermal resistance (no external heat sink) for the 7-lead TO-220 package mounted vertically, with ½ inch leads soldered to a PCB containing approximately 4 square inches of (1 oz.) copper area surrounding the leads.
(4) Junction to ambient thermal resistance for the 7-lead DDPAK mounted horizontally against a PCB area of 0.136 square inches (the same size as the DDPAK package) of 1 oz. (0.0014 in. thick) copper.
(5) Junction to ambient thermal resistance for the 7-lead DDPAK mounted horizontally against a PCB area of 0.4896 square inches (3.6 times the area of the DDPAK package) of 1 oz. (0.0014 in. thick) copper.
(6) Junction to ambient thermal resistance for the 7-lead DDPAK mounted horizontally against a PCB copper area of 1.0064 square inches (7.4 times the area of the DDPAK 3 package) of 1 oz. (0.0014 in. thick) copper. Additional copper area will reduce thermal resistance further.
(7) Junction to ambient thermal resistance for the 14-lead VSON mounted on a PCB copper area equal to the die attach paddle.
(8) Junction to ambient thermal resistance for the 14-lead VSON mounted on a PCB copper area using 12 vias to a second layer of copper equal to die attach paddle. Additional copper area will reduce thermal resistance further. For layout recommendations, see Application Note
AN-1187 Leadless Leadfram Package (LLP).
6.5 Electrical Characteristics: LM2673 – 3.3 V
Specifications apply for TA = TJ = 25°C unless otherwise noted. RADJ = 5.6 kΩ.
PARAMETER |
TEST CONDITIONS |
MIN(1) |
TYP(2) |
MAX(1) |
UNIT |
VOUT |
Output voltage |
VIN = 8 V to 40 V, 100 mA ≤ IOUT ≤ 5 A |
|
3.234 |
3.3 |
3.366 |
V |
over the entire junction temperature range of operation –40°C to 125°C |
3.201 |
|
3.399 |
η |
Efficiency |
VIN = 12 V, ILOAD = 5 A |
|
86% |
|
|
(1) All room temperature limits are 100% tested during production with TA = TJ = 25°C. All limits at temperature extremes are specified via correlation using standard Quality Control (SQC) methods. All limits are used to calculate Average Outgoing Quality Level (AOQL).
(2) Typical values are determined with TA = TJ = 25°C and represent the most likely norm.
6.6 Electrical Characteristics: LM2673 – 5 V
PARAMETER |
TEST CONDITIONS |
MIN(1) |
TYP(2) |
MAX(1) |
UNIT |
VOUT |
Output voltage |
VIN = 8 V to 40 V, 100 mA ≤ IOUT ≤ 5 A |
|
4.9 |
5 |
5.1 |
V |
over the entire junction temperature range of operation –40°C to 125°C |
4.85 |
|
5.15 |
η |
Efficiency |
VIN = 12 V, ILOAD = 5 A |
|
88% |
|
|
(1) All room temperature limits are 100% tested during production with TA = TJ = 25°C. All limits at temperature extremes are specified via correlation using standard Quality Control (SQC) methods. All limits are used to calculate Average Outgoing Quality Level (AOQL).
(2) Typical values are determined with TA = TJ = 25°C and represent the most likely norm.
6.7 Electrical Characteristics: LM2673 – 12 V
PARAMETER |
TEST CONDITIONS |
MIN(1) |
TYP(2) |
MAX(1) |
UNIT |
VOUT |
Output voltage |
VIN = 15 V to 40 V, 100 mA ≤ IOUT ≤ 5 A |
|
11.76 |
12 |
12.24 |
V |
over the entire junction temperature range of operation –40°C to 125°C |
11.64 |
|
12.36 |
η |
Efficiency |
VIN = 24 V, ILOAD = 5 A |
|
94% |
|
|
(1) All room temperature limits are 100% tested during production with TA = TJ = 25°C. All limits at temperature extremes are specified via correlation using standard Quality Control (SQC) methods. All limits are used to calculate Average Outgoing Quality Level (AOQL).
(2) Typical values are determined with TA = TJ = 25°C and represent the most likely norm.
6.8 Electrical Characteristics: LM2673 – Adjustable
PARAMETER |
TEST CONDITIONS |
MIN(1) |
TYP(2) |
MAX(1) |
UNIT |
VFB |
Feedback voltage |
VIN = 8 V to 40 V, 100 mA ≤ IOUT ≤ 5 A, VOUT programmed for 5 V |
|
1.186 |
1.21 |
1.234 |
V |
over the entire junction temperature range of operation –40°C to 125°C |
1.174 |
|
1.246 |
η |
Efficiency |
VIN = 12 V, ILOAD = 5 A |
|
88% |
|
|
(1) All room temperature limits are 100% tested during production with TA = TJ = 25°C. All limits at temperature extremes are specified via correlation using standard Quality Control (SQC) methods. All limits are used to calculate Average Outgoing Quality Level (AOQL).
(2) Typical values are determined with TA = TJ = 25°C and represent the most likely norm.
6.9 Electrical Characteristics – All Output Voltage Versions
Specifications are for TA = TJ = 25°C unless otherwise specified. Unless otherwise specified VIN = 12 V for the 3.3-V, 5-V, and Adjustable versions and VIN = 24 V for the 12-V version.
PARAMETER |
TEST CONDITIONS |
MIN |
TYP |
MAX |
UNIT |
DEVICE PARAMETERS |
IQ |
Quiescent current |
VFEEDBACK = 8 V for 3.3-V, 5-V, and ADJ versions, VFEEDBACK = 15 V for 12-V versions |
|
4.2 |
6 |
mA |
VADJ |
Current limit adjust voltage |
|
1.181 |
1.21 |
1.229 |
V |
over the entire junction temperature range of operation –40°C to 125°C |
1.169 |
|
1.246 |
ICL |
Current limit |
RADJ = 5.6 kΩ,(1) |
|
5.5 |
6.3 |
7.6 |
A |
over the entire junction temperature range of operation –40°C to 125°C |
5.3 |
|
8.1 |
IL |
Output leakage current |
VIN = 40 V, soft-start pin = 0 V |
VSWITCH = 0 V |
|
1 |
1.5 |
mA |
VSWITCH = –1 V |
|
6 |
15 |
RDS(ON) |
Switch ON-resistance |
ISWITCH = 5 A |
|
|
0.12 |
0.14 |
Ω |
over the entire junction temperature range of operation –40°C to 125°C |
|
|
0.225 |
fO |
Oscillator frequency |
Measured at switch pin |
|
|
260 |
|
kHz |
over the entire junction temperature range of operation –40°C to 125°C |
225 |
|
280 |
D |
Duty cycle |
Maximum duty cycle |
|
91% |
|
|
Minimum duty cycle |
|
0% |
|
|
IBIAS |
Feedback bias current |
VFEEDBACK = 1.3 V ADJ version only |
|
85 |
|
nA |
VSFST |
Soft-start threshold voltage |
|
|
0.63 |
|
V |
over the entire junction temperature range of operation –40°C to 125°C |
0.53 |
|
0.74 |
ISFST |
Soft-start pin current |
Soft-start pin = 0 V |
|
|
3.7 |
|
µA |
over the entire junction temperature range of operation –40°C to 125°C |
|
|
6.9 |
(1) The peak switch current limit is determined by the following relationship: ICL=37,125/ RADJ.
6.10 Typical Characteristics
Figure 1. Normalized Output Voltage
Figure 3. Efficiency vs Input Voltage
Figure 5. Switch Current Limit
Figure 7. Switching Frequency
Continuous Mode Switching Waveforms VIN = 20 V, VOUT = 5 V, ILOAD = 3 A L = 33 µH, COUT = 200 µF, COUTESR = 26 mΩ |
A: VSW Pin Voltage, 10 V/div |
B: Inductor Current, 1 A/div |
C: Output Ripple Voltage, 20 mV/div AC-Coupled |
Figure 9. Horizontal Time Base: 1 µs/div
Load Transient Response for Continuous Mode VIN = 20 V, VOUT = 5 V L = 33 µH, COUT = 200 µF, COUTESR = 26 mΩ |
A: Output Voltage, 100 mV//div, AC-Coupled. |
B: Load Current: 500-mA to 3-A Load Pulse |
Figure 11. Horizontal Time Base: 100 µs/div
Figure 2. Line Regulation
Figure 4. Efficiency vs ILOAD
Figure 6. Operating Quiescent Current
Figure 8. Feedback Pin Bias Current
Discontinuous Mode Switching Waveforms VIN = 20 V, VOUT = 5 V, ILOAD = 500 mA L = 10 µH, COUT = 400 µF, COUTESR = 13 mΩ |
A: VSW Pin Voltage, 10 V/div |
B: Inductor Current, 1 A/div |
C: Output Ripple Voltage, 20 mV/div AC-Coupled |
Figure 10. Horizontal Time Base: 1 µs//iv
Load Transient Response for Discontinuous Mode VIN = 20 V, VOUT = 5 V, L = 10 µH, COUT = 400 µF, COUTESR = 13 mΩ |
A: Output Voltage, 100 mV/div, AC-Coupled. |
B: Load Current: 200-mA to 3-A Load Pulse |
Figure 12. Horizontal Time Base: 200 µs/div