SLUSA41B JUNE   2010  – September 2016 TPS53311

PRODUCTION DATA.  

  1. 1 Features
  2. 2 Applications
  3. 3 Description
  4. 4 Revision History
  5. 5 Pin Configuration and Functions
  6. 6 Specifications
    1. 6.1 Absolute Maximum Ratings
    2. 6.2 ESD Ratings
    3. 6.3 Recommended Operating Conditions
    4. 6.4 Thermal Information
    5. 6.5 Electrical Characteristics
    6. 6.6 Typical Characteristics
  7. 7 Detailed Description
    1. 7.1 Overview
    2. 7.2 Functional Block Diagram
    3. 7.3 Feature Description
      1. 7.3.1 Soft Start
      2. 7.3.2 Power Good
      3. 7.3.3 Undervoltage Lockout (UVLO) Function
      4. 7.3.4 Overcurrent Protection
      5. 7.3.5 Overvoltage Protection
      6. 7.3.6 Undervoltage Protection
      7. 7.3.7 Overtemperature Protection
      8. 7.3.8 Output Discharge
      9. 7.3.9 Master and Slave Operation and Synchronization
    4. 7.4 Device Functional Modes
      1. 7.4.1 Operation Mode
      2. 7.4.2 Light Load Operation
      3. 7.4.3 Forced Continuous Conduction Mode
  8. 8 Application and Implementation
    1. 8.1 Application Information
    2. 8.2 Typical Application
      1. 8.2.1 Design Requirements
      2. 8.2.2 Detailed Design Procedure
        1. 8.2.2.1 Determine the Value of R1 and R2
        2. 8.2.2.2 Choose the Inductor
        3. 8.2.2.3 Choose the Output Capacitor(s)
        4. 8.2.2.4 Choose the Input Capacitor
        5. 8.2.2.5 Compensation Design
      3. 8.2.3 Application Curves
  9. 9 Power Supply Recommendations
  10. 10Layout
    1. 10.1 Layout Guidelines
    2. 10.2 Layout Example
  11. 11Device and Documentation Support
    1. 11.1 Documentation Support
      1. 11.1.1 Related Documentation
    2. 11.2 Receiving Notification of Documentation Updates
    3. 11.3 Community Resources
    4. 11.4 Trademarks
    5. 11.5 Electrostatic Discharge Caution
    6. 11.6 Glossary
  12. 12Mechanical, Packaging, and Orderable Information

Package Options

Mechanical Data (Package|Pins)
Thermal pad, mechanical data (Package|Pins)
Orderable Information

6 Specifications

6.1 Absolute Maximum Ratings

over operating free-air temperature range (unless otherwise noted)(1)
MIN MAX UNIT
Input voltage VIN, EN –0.3 7 V
VBST –0.3 17
VBST(with respect to SW) –0.3 7
FB, PS, VDD –0.3 3.7
Output voltage SW DC –1 7 V
Pulse < 20 ns, E = 5 µJ –3 10
PGD –0.3 7
COMP, SYNC –0.3 3.7
PGND –0.3 0.3
Operating temperature, TA –40 85 °C
Junction temperature, TJ –40 150 °C
Storage temperature, Tstg –55 150 °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.

6.2 ESD Ratings

VALUE UNIT
V(ESD) Electrostatic discharge Human-body model (HBM), per ANSI/ESDA/JEDEC JS-001(1) ±2000 V
Charged-device model (CDM), per JEDEC specification JESD22-C101(2) ±500
(1) JEDEC document JEP155 states that 500-V HBM allows safe manufacturing with a standard ESD control process.
(2) JEDEC document JEP157 states that 250-V CDM allows safe manufacturing with a standard ESD control process.

6.3 Recommended Operating Conditions

over operating free-air temperature range (unless otherwise noted)
MIN NOM MAX UNIT
Input voltage VIN 2.9 6 V
VDD 2.9 3.3 3.5
VBST –0.1 13.5
VBST(with respect to SW) –0.1 6
EN –0.1 6
FB, PS –0.1 3.5
Output voltage SW –1 6.5 V
PGD –0.1 6
COMP, SYNC –0.1 3.5
PGND –0.1 0.1
Junction temperature, TJ –40 125 °C

6.4 Thermal Information

THERMAL METRIC(1) TPS53311 UNIT
RGT (VQFN)
16 PINS
RθJA Junction-to-ambient thermal resistance 42.8 °C/W
RθJC(top) Junction-to-case (top) thermal resistance 51.3 °C/W
RθJB Junction-to-board thermal resistance 16 °C/W
ψJT Junction-to-top characterization parameter 0.7 °C/W
ψJB Junction-to-board characterization parameter 16 °C/W
RθJC(bot) Junction-to-case (bottom) thermal resistance 4.4 °C/W
(1) For more information about traditional and new thermal metrics, see the Semiconductor and IC Package Thermal Metrics application report.

6.5 Electrical Characteristics

over recommended free-air temperature range, VIN = 3.3 V, VVDD = 3.3 V, PGND = GND (unless otherwise noted)
PARAMETER TEST CONDITIONS MIN TYP MAX UNIT
SUPPLY: VOLTAGE, CURRENTS, AND UVLO
VIN VIN supply voltage Nominal input voltage 2.9 6 V
IVINSDN VIN shutdown current EN = LO 3 µA
VUVLO VIN UVLO threshold Ramp up, EN = HI 2.8 V
VUVLOHYS VIN UVLO hysteresis VIN UVLO Hysteresis 130 mV
VDD Internal circuitry supply voltage Nominal 3.3-V input voltage 2.9 3.3 3.5 V
IDDSDN VDD shut down current EN = LO 5 µA
IDD Standby current EN = HI, no switching 2.2 3.5 mA
VDDUVLO 3.3-V UVLO threshold Ramp up, EN = HI 2.8 V
VDDUVLOHYS 3.3-V UVLO hysteresis 75 mV
VOLTAGE FEEDBACK LOOP: VREF AND ERROR AMPLIFIER
VVREF VREF Internal precision reference voltage 0.6 V
TOLVREF VREF Tolerance 0°C ≤ TA ≤ 85°C –1% 1%
–40°C ≤ TA ≤ 85°C –1.25% 1.25%
UGBW(1) Unity gain bandwidth 14 MHz
AOL(1) Open loop gain 80 dB
IFBINT FB input leakage current Sourced from FB pin 30 nA
IEAMAX(1) Output sinking and sourcing current CCOMP = 20 pF 5 mA
SR(1) Slew rate 5 V/µs
OCP: OVER CURRENT AND ZERO CROSSING
IOCPL Overcurrent limit on upper FET When IOUT exceeds this threshold for 4 consecutive cycles. VIN = 3.3 V,
VOUT = 1.5 V with 1-µH inductor, TA = 25°C		 4.2 4.5 4.8 A
IOCPH One time overcurrent latch off on the lower FET Immediately shut down when sensed current reach this value. VIN = 3.3 V,
VOUT = 1.5 V with 1-µH inductor, TA = 25°C		 4.8 5.1 5.5 A
VZXOFF(1) Zero crossing comparator internal offset PGND – SW, SKIP mode –4.5 –3 –1.5 mV
PROTECTION: OVP, UVP, PGD, AND INTERNAL THERMAL SHUTDOWN
VOVP Overvoltage protection threshold voltage Measured at FB wrt. VREF 114% 117% 120%
VUVP Undervoltage protection threshold voltage Measured at FB wrt. VREF 80% 83% 86%
VPGDL PGD low threshold Measured at FB wrt. VREF 80% 83% 86%
VPGDU PGD upper threshold Measured at FB wrt. VREF 114% 117% 120%
VINMINPG Minimum VIN voltage for valid PGD at start up. Measured at VIN with 1-mA (or 2-mA) sink current on PGD pin at start up 1 V
THSD(1) Thermal shutdown Latch off controller, attempt soft-stop 130 140 150 °C
THSDHYS(1) Thermal Shutdown hysteresis Controller restarts after temperature has dropped 40 °C
LOGIC PINS: I/O VOLTAGE AND CURRENT
VPGPD PGD pulldown voltage Pulldown voltage with 4-mA sink current 0.2 0.4 V
IPGLK PGD leakage current Hi-Z leakage current, apply 3.3-V in off state –2 0 2 µA
RENPU Enable pullup resistor 1.35 MΩ
VENH EN logic high threshold 1.1 1.18 1.3 V
VENHYS EN hysteresis 0.18 0.24 V
PSTHS PS mode threshold voltage Level 1 to level 2(2) 0.12 V
Level 2 to level 3 0.4
Level 3 to level 4 0.8
Level 4 to level 5 1.4
Level 5 to level 6 2.2
IPS PS source 10-µA pullup current when enabled 8 10 12 µA
fSYNCSL Slave SYNC frequency range Versus nominal switching frequency –20% 20%
PWSYNC SYNC low pulse width 110 ns
ISYNC SYNC pin sink current 10 µA
VSYNCTHS(1) SYNC threshold Falling edge 1 V
VSYNCHYS(1) SYNC hysteresis 0.5 V
BOOT STRAP: VOLTAGE AND LEAKAGE CURRENT
IVBSTLK VBST leakage current VIN = 3.3 V, VVBST = 6.6 V, TA = 25°C 1 µA
TIMERS: SS, FREQUENCY, RAMP, ON TIME AND I/O TIMING
tSS_1 Delay after EN asserting EN = HI, master or HEF mode 0.2 ms
tSS_2 Delay after EN asserting EN = HI, slave waiting time 0.5 ms
tSS_3 Soft-start ramp-up time Rising from VSS = 0 V to VSS = 0.6 V 0.4 ms
tPGDENDLY PGD startup delay time Rising from VSS = 0 V to VSS = 0.6 V,
from VSS reaching 0.6 V to VPGD going high		 0.4 ms
tOVPDLY Overvoltage protection delay time Time from FB out of 20% of VREF to OVP fault 1.0 1.7 2.5 µs
tUVPDLY Undervoltage protection delay time Time from FB out of –20% of VREF to UVP fault 11 µs
fSW Switching frequency control Forced CCM mode 0.99 1.1 1.21 MHz
Ramp amplitude(1) 2.9 V < VIN < 6 V VIN/4 V
tMIN(off) Minimum OFF time FCCM mode or DE mode 100 140 ns
HEF mode 175 250
DMAX Maximum duty cycle FCCM mode and DE mode, fSW = 1.1 MHz,
0°C ≤ TA ≤ 85°C		 84% 89%
HEF mode, fSW = 1.1 MHz, 0°C ≤ TA ≤ 85°C 75% 81%
RSFTSTP Soft-discharge transistor resistance VEN = Low, VIN = 3.3 V, VOUT = 0.5 V 60 Ω
(1) Ensured by design. Not production tested.
(2) See PS pin description for levels.

6.6 Typical Characteristics

Inductor IN06142 (1 µH, 5.4 mΩ) is used.
TPS53311 eff_skip33_lusa41.gif Figure 1. Efficiency vs Output Current,
Skip Mode, VIN = 3.3 V
TPS53311 eff_skip50_lusa41.gif Figure 3. Efficiency vs Output Current,
Skip Mode, VIN = 5 V
TPS53311 vfb_v_t_lusa41.gif Figure 5. Feedback Voltage vs Ambient Temperature
TPS53311 f_v_iout33_lusa41.gif Figure 7. Frequency vs Output Current
at VIN = 3.3 V
TPS53311 startup1x_lusa41.gif Figure 9. Normal Start-Up Waveform
TPS53311 startup3x_lusa41.gif Figure 11. Soft-Stop Waveform
TPS53311 eff_fccm33_lusa41.gif Figure 2. Efficiency vs Output Current,
FCCM, VIN = 3.3 V
TPS53311 eff_fccm50_lusa41.gif Figure 4. Efficiency vs Output Current,
FCCM, VIN = 5 V
TPS53311 deltavo_v_vo_lusa41.gif Figure 6. Output Voltage Change vs Output Current
TPS53311 f_v_iout50_lusa41.gif Figure 8. Frequency vs Output Current
at VIN = 5 V
TPS53311 startup2x_lusa41.gif Figure 10. Prebias Start-Up Waveform
TPS53311 t_v_iout_lusa41.gif Figure 12. Safe Operating Area