SLTS278J November   2010  – March 2020 PTH08T250W

PRODUCTION DATA.  

  1. 1 Features
  2. 2 Applications
  3. 3 Description
  4. 4 Revision History
  5. 5 Description (continued)
  6. 6 Pin Configuration and Functions
    1. Table 1. Pin Functions
  7. 7 Specifications
    1. 7.1 Absolute Maximum Ratings
    2. 7.2 Electrical Characteristics
    3. 7.3 Typical Characteristics (VI = 12 V)
    4. 7.4 Typical Characteristics (VI = 5 V)
  8. 8 Detailed Description
    1. 8.1 Overview: TurboTrans™ Technology
    2. 8.2 Feature Description
      1. 8.2.1 Soft-Start Power-Up
      2. 8.2.2 Differential Output Voltage Remote Sense
      3. 8.2.3 Overcurrent Protection
      4. 8.2.4 Overtemperature Protection (OTP)
  9. 9 Application and Implementation
    1. 9.1 Typical Application
      1. 9.1.1 Detailed Design Procedure
        1. 9.1.1.1  Adjusting the Output Voltage
        2. 9.1.1.2  Capacitor Recommendations for the PTH08T250W Power Module
          1. 9.1.1.2.1 Capacitor Technologies
          2. 9.1.1.2.2 Input Capacitor (Required)
          3. 9.1.1.2.3 Input Capacitor Information
          4. 9.1.1.2.4 Output Capacitor (Required)
          5. 9.1.1.2.5 Output Capacitor Information
          6. 9.1.1.2.6 TurboTrans Output Capacitance
          7. 9.1.1.2.7 Non-TurboTrans Output Capacitance
          8. 9.1.1.2.8 Designing for Fast Load Transients
          9. 9.1.1.2.9 Capacitor Table
        3. 9.1.1.3  TurboTrans™ Technology
        4. 9.1.1.4  TurboTrans™ Selection
          1. 9.1.1.4.1 PTH08T250W Type B Capacitors
            1. 9.1.1.4.1.1 RTT Resistor Selection
          2. 9.1.1.4.2 PTH08T250W Type C Capacitors
            1. 9.1.1.4.2.1 RTT Resistor Selection
        5. 9.1.1.5  Undervoltage Lockout (UVLO)
          1. 9.1.1.5.1 UVLO Adjustment
        6. 9.1.1.6  On/Off Inhibit
        7. 9.1.1.7  Current Sharing
          1. 9.1.1.7.1 Current Sharing and TurboTrans
            1. 9.1.1.7.1.1 Current Sharing Thermal Derating Curves
            2. 9.1.1.7.1.2 Current Sharing Layout
        8. 9.1.1.8  Prebias Startup Capability
        9. 9.1.1.9  SmartSync Technology
        10. 9.1.1.10 Auto-Track™ Function
          1. 9.1.1.10.1 How Auto-Track™ Works
          2. 9.1.1.10.2 Typical Auto-Track Application
          3. 9.1.1.10.3 Notes on Use of Auto-Track™
  10. 10Device and Documentation Support
    1. 10.1 Receiving Notification of Documentation Updates
    2. 10.2 Support Resources
    3. 10.3 Trademarks
    4. 10.4 Electrostatic Discharge Caution
    5. 10.5 Glossary
  11. 11Mechanical, Packaging, and Orderable Information
    1. 11.1 Tape, Reel, and Tray Drawings

Package Options

Refer to the PDF data sheet for device specific package drawings

Mechanical Data (Package|Pins)
  • BCU|22
  • ECT|22
  • ECU|22
Thermal pad, mechanical data (Package|Pins)
Orderable Information

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.