7.2 Electrical Characteristics
TA = 25°C, VI = 12 V, VO = 3.3 V, CI = 1000 µF, CO = 660 µF, and IO = IO max (unless otherwise stated)
| PARAMETER |
TEST CONDITIONS |
MIN |
TYP |
MAX |
UNIT |
| IO |
Output current |
Over VO range |
25°C, natural convection |
0 |
|
48 |
A |
| 60°C, 200 LFM |
0 |
|
50 |
| VI |
Input voltage range |
Over IO range |
0.7 ≤ VO < 1.2 |
4.5 |
|
14 (2) |
V |
| 1.2 ≤ VO ≤ 3.6 |
4.5 |
|
14 |
| VOADJ |
Output voltage adjust range |
Over IO range |
0.7 |
|
3.6 |
V |
| VO |
Set-point voltage tolerance |
|
|
±0.5 |
±1 (1) |
%Vo |
| Temperature variation |
–40°C < TA < 85°C |
|
±0.3 |
|
%Vo |
| Line regulaltion |
Over VI range |
|
±5 |
|
mV |
| Load regulation |
Over IO range |
|
±5 |
|
mV |
| Total output variation |
Includes set-point, line, load, –40°C ≤ TA ≤ 85°C |
|
|
±1.5 (1) |
%Vo |
| η |
Efficiency |
IO = 30 A |
RSET = 1.62 kΩ, VO = 3.3 V |
|
94% |
|
|
| RSET = 5.23 kΩ, VO = 2.5 V |
|
93% |
|
|
| RSET = 12.7 kΩ, VO = 1.8 V |
|
91% |
|
|
| RSET = 19.6 kΩ, VO = 1.5 V |
|
90% |
|
|
| RSET = 35.7 kΩ, VO = 1.2 V |
|
88% |
|
|
| RSET = 63.4 kΩ, VO = 1.0 V |
|
86% |
|
|
| RSET = open, VO = 0.7 V |
|
83% |
|
|
|
VO Ripple (peak-to-peak) |
20-MHz bandwidth |
|
10 (2) |
|
mVPP |
| ILIM |
Overcurrent threshold |
Reset, followed by auto-recovery |
|
85 |
|
A |
| ttr |
Transient response |
2.5 A/µs load step
50 to 100% IOmax |
w/o TurboTrans
CO = 660 μF, Type C |
Recovery time |
|
100 |
|
µs |
| ΔVtr |
VO over/undershoot |
|
160 |
|
mV |
| ttrTT |
w/ TurboTrans
CO = 3300 μF, Type C
RTT = short |
Recovery time |
|
100 |
|
µs |
| ΔVtrTT |
VO over/undershoot |
|
45 |
|
mV |
| IIL |
Track input current (pin 20) |
Pin to GND |
|
|
–130(3) |
µA |
| dVtrack/dt |
Track slew rate capability |
CO ≤ CO (max) |
|
|
1 |
V/ms |
| UVLOADJ |
Adjustable Under-voltage lockout (pin 21) |
VI increasing, RUVLO = OPEN |
|
4.3 |
4.45 |
V |
| VI decreasing, RUVLO = OPEN |
4.0 |
4.2 |
|
| Hysteresis, RUVLO ≤ 127 kΩ |
|
1.0 |
|
|
Inhibit control (pin 21) |
Input high voltage (VIH) |
|
|
Open(4) |
V |
| Input low voltage (VIL) |
-0.2 |
|
0.6 |
| Input low current (IIL ), Pin 21 to GND |
|
-125 |
|
µA |
| Iin |
Input standby current |
Inhibit (pin 21) to GND, Track (pin 20) open |
|
35 |
|
mA |
| fs |
Switching frequency |
Over VI and IO ranges, SmartSync (pin 22) to GND |
|
600 (5) |
|
kHz |
| fSYNC |
Synchronization (SYNC)
control (pin 22) |
Synchronization frequency applied to pin 22 |
240 (5) |
|
400 (5) |
kHz |
| VSYNCH |
SYNC High-Level Input Voltage |
2.0 |
|
5.5 |
V |
| VSYNCL |
SYNC Low-Level Input Voltage |
|
|
0.8 |
V |
| tSYNC |
SYNC Minimum Pulse Width |
200 |
|
|
nSec |
| CI |
External input capacitance |
Nonceramic |
1000 (6) |
|
|
µF |
| Ceramic |
|
22 |
|
| CO |
External output capacitance |
without TurboTrans |
Capacitance Value |
Non-ceramic |
660 (7) |
|
8000 (8) |
µF |
| Ceramic |
|
|
1000(10) |
| Equivalent series resistance (non-ceramic) |
3 |
|
|
mΩ |
| with TurboTrans |
Capacitance Value |
Non-ceramic |
660 (7)(9) |
|
|
µF |
| Ceramic |
|
|
1000(10) |
| Capacitance × ESR product (CO × ESR) |
1000 |
|
10000 (9) |
µF×mΩ |
| MTBF |
Reliability |
Per Telcordia SR-332, 50% stress,
TA = 40°C, ground benign |
2.79 |
|
|
106 Hr |
(1) The set-point voltage tolerance is affected by the tolerance and stability of RSET. The stated limit is unconditionally met if RSET has a tolerance of 1% with 100 ppm/°C or better temperature stability.
(2) For output voltages less than 1.2 V, the output ripple may increase (up to 2×) when operating at input voltages greater than (VO × 12). Adjusting the switching frequency using the SmartSync feature may increase or decrease this ratio. Review the SmartSync section of the Application Information for further guidance.
(3) A low-leakage (<100 nA), open-drain device, such as MOSFET or voltage supervisor IC, is recommended to control pin 20. The open-circuit voltage is less than 8 Vdc.
(4) Do not place an external pull-up on this pin. If it is left open-circuit, the module operates when input power is applied. A small, low-leakage (<100 nA) MOSFET is recommended for control. For additional information, see the related application section.
(5) The PTH08T250W is a two-phase power module. Each phase switches at 300 kHz typical, 180° out-of-phase from one another. The over-all switching frequency is 600 kHz typical. SmartSync controls the frequency of an individual phase. When using SmartSync the external synchronization frequency must be present before a valid input voltage is present, or before the release of inhibit control.
(6) A 1000 µF electrolytic input capacitor is required for proper operation. When operating at an input voltage greater than 8V the minimum required input capacitance may be reduced to 560μF. The input capacitor must be rated for a minimum of 600 mA rms of ripple current.
(7) 660 µF of external non-ceramic output capacitance is required for basic operation. Adding additional capacitance at the load further improves transient response. See the Capacitor Application Information section and the TuboTrans Technology section for more guidance.
(8) This is the calculated maximum when not using TurboTrans technology. This value includes both ceramic and non-ceramic capacitors. The minimum ESR requirement often results in a lower value of output capacitance. See the Capacitor Application Information section for more guidance.
(9) When using
TurboTrans technology, a minimum value of output capacitance is required for proper operation. Additionally, low ESR capacitors are required for proper operation. See the
Overview: TurboTrans™ Technology section for further guidance.
(10) Ceramic output capacitance may be added in addition to the required non-ceramic output capacitance. The amount of ceramic capacitance must be less than the non-ceramic capacitance, not to exceed 1000 µF.