6 Specifications
6.1 Absolute Maximum Ratings
over operating free-air temperature range (unless otherwise noted)(1)(2)
|
MIN |
MAX |
UNIT |
AVIN, PVIN |
–0.5 |
24 |
V |
SW voltage |
–0.5 |
24 |
V |
Boost voltage |
–0.5 |
28 |
V |
Boost to SW voltage |
–0.5 |
6 |
V |
FB voltage |
–0.5 |
3 |
V |
SYNC voltage |
–0.5 |
6 |
V |
EN voltage |
–0.5 |
VIN + 0.3 |
V |
Soldering, infrared reflow (5 s) |
|
260 |
°C |
Junction temperature, TJ |
|
150 |
°C |
Storage temperature, Tstg |
–65 |
150 |
°C |
(1) 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.
(2) If Military/Aerospace specified devices are required, please contact the Texas Instruments Sales Office/ Distributors for availability and specifications.
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) Human body model, 1.5 kΩ in series with 100 pF.
6.3 Recommended Operating Conditions
over operating free-air temperature range (unless otherwise noted)(1)
|
MIN |
MAX |
UNIT |
AVIN, PVIN |
3 |
20 |
V |
SW voltage |
–0.5 |
20 |
V |
Boost voltage |
–0.5 |
24 |
V |
Boost to SW voltage |
3 |
5.5 |
V |
Junction temperature |
–40 |
125 |
°C |
(1) Absolute Maximum Ratings indicate limits beyond which damage to the device may occur, including inoperability and degradation of device reliability and/or performance. Functional operation of the device and/or non-degradation at the Absolute Maximum Ratings or other conditions beyond those indicated in the recommended Operating Ratings is not implied. The recommended Operating Ratings indicate conditions at which the device is functional and should not be operated beyond such conditions.
6.4 Thermal Information
THERMAL METRIC(1) |
LM2734x, LM2734x-Q1 |
UNIT |
DSC (WSON) |
DGQ (MSOP-PowerPAD) |
10 PINS |
10 PINS |
RθJA |
Junction-to-ambient thermal resistance(2) |
47.6 |
49.5 |
°C/W |
RθJC(top) |
Junction-to-case (top) thermal resistance |
36.5 |
53.6 |
°C/W |
RθJB |
Junction-to-board thermal resistance |
22.5 |
33.7 |
°C/W |
ψJT |
Junction-to-top characterization parameter |
0.4 |
3.9 |
°C/W |
ψJB |
Junction-to-board characterization parameter |
22.7 |
33.4 |
°C/W |
RθJC(bot) |
Junction-to-case (bottom) thermal resistance |
4.7 |
3.5 |
°C/W |
(2) Thermal shutdown will occur if the junction temperature exceeds 165°C. The maximum power dissipation is a function of TJ(MAX), RθJA and TA. The maximum allowable power dissipation at any ambient temperature is PD = (TJ(MAX) – TA)/ RθJA. All numbers apply for packages soldered directly onto a 3" × 3" PCB with 2 oz. copper on 4 layers in still air.
6.5 Electrical Characteristics
TJ = 25°C, VIN = 12 V, and VBOOST – VSW = 4.3 V (unless otherwise noted)
PARAMETER |
TEST CONDITIONS |
MIN |
TYP |
MAX |
UNIT |
SYSTEM PARAMETERS |
VFB |
Feedback voltage |
TJ = 0°C to 85°C |
0.99 |
1 |
1.01 |
V |
TJ = –40°C to 125°C |
0.984 |
1 |
1.014 |
ΔVFB/ΔVIN |
Feedback voltage line regulation |
VIN = 3 V to 20 V |
|
0.003% |
|
V |
IFB |
Feedback input bias current |
TJ = 25°C |
|
20 |
|
nA |
TJ = –40°C to 125°C |
|
|
100 |
OVP |
Overvoltage protection |
VFB at which PWM halts |
|
1.13 |
|
V |
UVLO |
Undervoltage lockout |
VIN rising until VSW is switching |
TJ = 25°C |
|
2.75 |
|
V |
TJ = –40°C to 125°C |
2.6 |
|
2.9 |
Undervoltage hysteresis |
VIN falling from UVLO |
TJ = 25°C |
|
0.47 |
|
TJ = –40°C to 125°C |
0.3 |
|
0.6 |
SS |
Soft-start time |
|
0.5 |
1 |
1.5 |
ms |
IQ |
Quiescent current |
IQ = IQ_AVIN + IQ_PVIN |
VFB = 1.1 (not switching) |
|
2.4 |
|
mA |
VEN = 0 V (shutdown) |
|
70 |
|
nA |
IBOOST |
Boost pin current |
fSW= 2 MHz |
TJ = 25°C |
|
8.2 |
|
mA |
TJ = –40°C to 125°C |
|
|
10 |
fSW= 1 MHz |
|
4.4 |
6 |
OSCILLATOR |
fSW |
Switching frequency |
SYNC = GND |
TJ = 25°C |
|
2 |
|
MHz |
TJ = –40°C to 125°C |
1.75 |
|
2.3 |
VFB_FOLD |
FB pin voltage |
SYNC input is overridden |
|
0.53 |
|
V |
fFOLD_MIN |
Frequency foldback minimum |
VFB = 0 V |
|
220 |
250 |
kHz |
LOGIC INPUTS (EN, SYNC) |
fSYNC |
SYNC frequency range |
|
1 |
|
2.35 |
MHz |
VIL |
EN, SYNC logic low threshold |
Logic falling edge |
|
|
0.4 |
V |
VIH |
EN, SYNC logic high threshold |
Logic rising edge |
1.8 |
|
|
tSYNC_HIGH |
SYNC, time required above VIH to ensure a logical high |
|
|
|
100 |
ns |
tSYNC_LOW |
SYNC, time required below VIL to ensure a logical low |
|
|
|
100 |
ns |
ISYNC |
SYNC pin current |
VSYNC < 5 V |
|
20 |
|
nA |
IEN |
Enable pin current |
VEN = 3 V |
|
6 |
15 |
µA |
VIN = VEN = 20 V |
|
50 |
100 |
INTERNAL MOSFET |
RDS(ON) |
Switch ON-resistance |
TJ = 25°C |
|
150 |
|
mΩ |
TJ = –40°C to 125°C |
|
|
320 |
ICL |
Switch current limit |
TJ = –40°C to 125°C |
LM27342 |
2.5 |
|
4 |
A |
LM27341 |
2 |
|
3.7 |
DMAX |
Maximum duty cycle |
SYNC = GND |
TJ = 25°C |
|
93% |
|
|
TJ = –40°C to 125°C |
85% |
|
|
tMIN |
Minimum ON-time |
|
|
65 |
|
ns |
ISW |
Switch leakage current |
|
|
40 |
|
nA |
BOOST LDO |
VLDO |
Boost LDO output voltage |
|
|
3.9 |
|
V |
THERMAL |
TSHDN |
Thermal shutdown temperature |
Junction temperature rising |
|
165 |
|
°C |
Thermal shutdown hysteresis |
Junction temperature falling |
|
15 |
|
6.6 Typical Characteristics
TA = 25°C, VIN = 12 V, and VBOOST – VSW = 4.3 V (unless otherwise noted)
Figure 1. Efficiency vs Load Current
See Figure 34
Figure 3. Efficiency vs Load Current
See Figure 40
Figure 5. Efficiency vs Load Current
See Figure 49
VIN = 10 V to 15 V |
VOUT = 3.3 V |
No CFF |
Figure 7. Line Transient
See Figure 43
Figure 9. Short Circuit
Figure 11. Soft Start With EN Tied to VIN
VIN = 12 V |
L = 2.2 µH |
Iout =1 A |
VOUT = 5 V |
COUT = 44 µF |
|
Figure 13. Bode Plot
See Figure 34
VIN = 5 V |
L = 1.0 µH |
Iout =1 A |
VOUT = 1.8 V |
COUT = 44 µF |
|
Figure 15. Bode Plot
See Figure 49
Figure 17. Sync Functionality
Figure 19. Oscillator Frequency vs Temperature
Figure 21. VFB vs Temperature
Figure 23. Current Limit vs Temperature
Figure 25. IQ (Shutdown) vs Temperature
VOUT = 5 V |
IOUT = 100 mA – 2 A at Slewrate = 2 A / µs |
Figure 2. Load Transient
See Figure 34
VOUT = 3.3 V |
IOUT = 100 mA – 2 A at Slewrate = 2 A / µs |
Figure 4. Load Transient
See Figure 40
VOUT = 1.8 V |
IOUT = 100 mA – 2 A at Slewrate = 2 A / µs |
Figure 6. Load Transient
See Figure 49
VIN = 10 V to 15 V |
VOUT = 3.3 V |
|
Figure 8. Line Transient
See Figure 40
Figure 10. Short-Circuit Release
Figure 12. Soft Start With EN Tied to VIN
VIN = 12 V |
L = 1.5 µH |
Iout =1 A |
VOUT = 3.3 V |
COUT = 44 µF |
|
Figure 14. Bode Plot
See Figure 40
VIN = 5 V |
L = 0.56 µH |
Iout =1 A |
VOUT = 1.2 V |
COUT = 68 µF |
|
Figure 16. Bode Plot
See Figure 55
Figure 18. Loss of Synchronization
Figure 20. Oscillator Frequency vs VFB
Figure 22. VFB vs VIN
Figure 24. RDSON vs Temperature
Figure 26. IEN vs VEN