SLVSAE1B October   2010  – September 2015 TPS65708

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 Parameter Measurement Information
    1. 7.1 Setup
  8. 8 Detailed Description
    1. 8.1 Overview
    2. 8.2 Functional Block Diagram
    3. 8.3 Feature Description
      1. 8.3.1  DC-DC Converters
      2. 8.3.2  Power Save Mode
      3. 8.3.3  Dynamic Voltage Positioning
      4. 8.3.4  Soft Start
      5. 8.3.5  100% Duty Cycle Low Dropout Operation
      6. 8.3.6  180° Out-of-Phase Operation
      7. 8.3.7  Undervoltage Lockout and Enable for DCDC1, DCDC2, LDO1, and LDO2
      8. 8.3.8  Output Voltage Discharge
      9. 8.3.9  Power-Up Sequencing
      10. 8.3.10 Short-Circuit Protection
      11. 8.3.11 Thermal Shutdown
      12. 8.3.12 LDOs
      13. 8.3.13 LED Driver
    4. 8.4 Device Functional Modes
  9. 9 Application and Implementation
    1. 9.1 Application Information
    2. 9.2 Typical Applications
      1. 9.2.1 Powering All Rails from the Input Supply of 5 V
        1. 9.2.1.1 Design Requirements
        2. 9.2.1.2 Detailed Design Procedure
          1. 9.2.1.2.1 Output Filter Design (Inductor and Output Capacitor)
            1. 9.2.1.2.1.1 Inductor Selection
            2. 9.2.1.2.1.2 Output Capacitor Selection
            3. 9.2.1.2.1.3 Input Capacitor Selection
        3. 9.2.1.3 Application Curve
      2. 9.2.2 Powering the LDOs From the Output of the DC-DC Converters to Improve Efficiency
  10. 10Power Supply Recommendations
  11. 11Layout
    1. 11.1 Layout Guidelines
    2. 11.2 Layout Example
  12. 12Device and Documentation Support
    1. 12.1 Device Support
      1. 12.1.1 Third-Party Products Disclaimer
    2. 12.2 Community Resources
    3. 12.3 Trademarks
    4. 12.4 Electrostatic Discharge Caution
    5. 12.5 Glossary
  13. 13Mechanical, 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
Voltage All pins except A/PGND pins with respect to AGND –0.3 7 V
Pin VLDO1 and VLDO2 with respect to AGND –0.3 3.6 V
Current L1, L2, VLDO1, VLDO2, PGND 700 mA
AGND, ISINK 50 mA
All other pins 3 mA
Operating free-air temperature, TA –40 85 °C
Maximum junction temperature, TJ 125 °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 and functional operation of the device at these or any other conditions beyond those indicated under Recommended Operating Conditions is not implied. 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
VIN1/2 Input voltage for step-down converter DCDC1and DCDC2 3.6 6 V
VOUTDCDC1/2 Output voltage for DCDC1 and DCDC2 step-down converter 0.8 3.3 V
IOUTDCDC1 DC output current at L1 or L2 400 mA
L Inductor at L1 or L2(1) 1 1.5 2.2 µH
VINLDO1 Input voltage for LDO1 1.7 6 V
VLDO Output voltage for LDO1 and LDO2 0.8 3.3 V
VINLDO2 Input voltage for LDO2 1.7 6 V
ILDO Output current at LDO1 or LDO2 200 mA
CINDCDC1/2 Input capacitor at VIN1 and VIN2 4.7 µF
COUTDCDC1/2 Output capacitor at VOUT1, VOUT2 4.7 10 22 µF
COUTLDO1/2 Output capacitor at VLDO1, VLDO2 2.2 µF
TA Operating ambient temperature –40 85 °C
TJ Operating junction temperature –40 125 °C
(1) To support a typical inductor value of 1.5 µH, the minimum inductance can go as low as 1 µH. It is not recommended to use a 1-µH labeled inductor as the inductance will drop significantly below 1 µH in operation due to initial tolerances and saturation.

6.4 Thermal Information

THERMAL METRIC(1) TPS65708 UNIT
YZH (DSBGA)
16 PINS
RθJA Junction-to-ambient thermal resistance 75 °C/W
RθJC(top) Junction-to-case (top) thermal resistance 22 °C/W
RθJB Junction-to-board thermal resistance 26 °C/W
ψJT Junction-to-top characterization parameter 0.2 °C/W
ψJB Junction-to-board characterization parameter 24 °C/W
RθJC(bot) Junction-to-case (bottom) thermal resistance N/A °C/W
(1) For more information about traditional and new thermal metrics, see the Semiconductor and IC Package Thermal Metrics application report, SPRA953.

6.5 Electrical Characteristics

Unless otherwise noted: VIN1 = VIN2 = VCC = 5 V, L = 1.5 µH, COUTDCDCx = 10 µF, COUTLDOx = 2.2 µF, TA = –40°C to 85°C.
PARAMETER TEST CONDITIONS MIN TYP MAX UNIT
SUPPLY CURRENT
IQ Operating quiescent current DCDCx and LDOx DCDC1, DCDC2, LDO1 and LDO2 enabled,
IOUT = 0 mA, MODE = 0; (PFM mode)
ISINK in standby for PWM = 0		 140 200 μA
DCDC1, DCDC2, LDO1 and LDO2 enabled,
IOUT = 0 mA, MODE = 1 ; (PWM mode)
ISINK in standby if PWM = 0;
Not including inductor losses		 4 mA
DCDC1, DCDC2, LDO1 and LDO2 enabled,
IOUT = 0 mA, MODE = 0; (PFM mode) ;
ISINK in standby PWM = 0;
During power-up sequencing		 170 μA
ISD Shutdown Current DCDCx, LDOx and ISINK disabled;
VCC < 1.8 V		 6 15 μA
DIGITAL PINS ( MODE)
VIH High-Level Input Voltage for MODE 1.2 VCC V
VIL Low-Level Input Voltage for MODE 0 0.4 V
Ilkg Input Leakage Current MODE tied to GND or VIN1 / VIN2 0.01 0.1 μA
UNDERVOLTAGE LOCKOUT (UVLO), SENSED AT PIN VCC
UVLO Internal undervoltage lockout threshold VCC, VIN1, VIN2 rising 3.5 3.6 3.7 V
Internal undervoltage lockout threshold hysteresis VCC, VIN1, VIN2 falling 130 mV
STEP-DOWN CONVERTERS
VIN1 Input voltage for DCDC1 3.5 6 V
VIN2 Input voltage for DCDC2 3.5 6 V
POWER SWITCH
RDS(on) High-side MOSFET ON-resistance VIN1 / VIN2 = 3.6 V 250 400 mΩ
Low-side MOSFET ON-resistance VIN1 / VIN2 = 3.6 V 150 300 mΩ
ILIMF Forward current limit 3.6 V ≤ VIN1 / VIN2 ≤ 6 V 650 820 1050 mA
IO DC output current VIN1 / VIN2 > 3.5 V , L = 1.5 µH 400 mA
OSCILLATOR
fSW Oscillator frequency 2.03 2.25 2.48 MHz
OUTPUT
VOUT1 DCDC1 default output voltage VIN1 ≥ 3.6 V 3.3 V
VOUT2 DCDC2 default output voltage VIN2 ≥ 3.6 V 1.8 V
IFB FB pin input current DC-DC converter input voltage below undervoltage lockout threshold 0.1 µA
RFB FB pin input resistance due to internal voltage divider DC-DC converter input voltage above undervoltage lockout threshold; VOUT = 3.3 V 990 kΩ
RFB FB pin input resistance due to internal voltage divider DC-DC converter input voltage above undervoltage lockout threshold; VOUT = 1.8 V 585 kΩ
VOUT DC output voltage accuracy(1) VIN1 and VIN2 = 3.6 V to 6 V, +1% voltage positioning active; PFM operation,
0 mA < IOUT < IOUTmax		 1.25% 3%
DC output voltage accuracy VIN1 / VIN2 = 3.3V to 6V, PWM operation,
0 mA < IOUT < IOUTmax		 –1.5% 1.5%
DC output voltage load regulation PWM operation 0.5 %/A
tStart Start-up time Time from UVLO is exceeded (Vin > 3.6 V) to Start switching 200 µs
tRamp VOUT ramp time Time to ramp from 5% to 95% of VOUT 250 µs
RDIS Internal discharge resistor at L1 and L2 DCDCx disabled; 1 V < VIN1/2 < 3.6 V 300 400 550 Ω
THERMAL PROTECTION SEPARATELY FOR DCDC1, DCDC2 and LDO1
TSD Thermal shutdown Increasing junction temperature 150 °C
Thermal shutdown hysteresis Decreasing junction temperature 30 °C
VLDO1, VLDO2 LOW DROPOUT REGULATOR
VINLDO Input voltage range for LDO1 and LDO2 1.7 6 V
VLDO1 LDO1 Default Output Voltage (1) 2.8 V
VLDO2 LDO2 Default Output Voltage 1.2 V
IO Output current for LDO1 and LDO2 200 mA
ISC LDO1 and LDO2 short circuit current limit VLDOx = GND 260 360 550 mA
Dropout voltage at LDOx IO = 200 mA; VINLDOx = 3.3 V 200 mV
Dropout voltage at LDOx IO = 200 mA; VINLDOx = 1.8 V 300 mV
Output voltage accuracy for LDO1 and LDO2 IO = 200 mA –2% 2%
Line regulation for LDO1 and LDO2 VINLDO = VLDO + 0.5 V (min 1.7 V) to 6 V,
IO = 50 mA		 –1% 1%
Load regulation for LDO1 and LDO2 IO = mA to 200 mA –1.5% 1%
PSRR Power Supply Rejection Ratio f = 10 kHz, COUT ≥ 2.2 μF VINLDOx = 5 V, VOUT = 2.8 V, IOUT = 100 mA 50 dB
Vn Output noise voltage VOUT = 2.8 V, BW = 10 Hz to 100 kHz 160 µV RMS
tRamp VOUT ramp time Internal soft start when LDO is enabled;
Time to ramp from 5% to 95% of VOUT		 250 µs
RDIS Internal discharge resistor at VLDO1 and VLDO2 VIN < UVLO 200 400 550 Ω
LED CURRENT SINK
ILED Isink Current (LED current for 100% duty cycle) Set internally by EEPROM to 7.5 mA; available current range from 7.5 mA to 30 mA; contact factory about default settings other than 7.5 mA 7.5 mA
Minimum voltage drop from ISINK to AGND needed for proper regulation at 7.5 mA ≤ ISINK ≤ 20 mA 0.4 V
Minimum voltage drop from ISINK to AGND needed for proper regulation at 20 mA < ISINK ≤ 30 mA 0.55 V
ISINK accuracy ISINK ≥ 10 mA –5% 5%
ISINK accuracy 7.5 mA ≤ ISINK < 10 mA –10% 10%
PWM duty cycle 5% 100%
PWM frequency 50 kHz
VIH High-Level Input Voltage for PWM pin ISINK is enabled 1.2 VCC V
VIL Low-Level Input Voltage for PWM pin ISINK is high resistive 0 0.4 V
Ilkg Input Leakage Current on PWM pin 0.01 0.1 μA
ISINK rise / fall time V(ISINK) ≥ 0.4 V for 7.5 mA ≤ ISINK ≤ 20 mA; or
V(ISINK) > 0.6 V for 20 mA < ISINK ≤ 30 mA		 500 ns
ISINK rise / fall time V(ISINK) ≤ 0.6 V; 20 mA < ISINK ≤ 30 mA 700 ns
(1) VINLDO > 2.8 V

6.6 Typical Characteristics

Table 1. Table Of Graphs

FIGURE
η Efficiency DCDC (VO = 3.3 V) vs Load current / PFM mode Figure 1
η Efficiency DCDC (VO = 3.3 V) vs Load current / PWM mode Figure 2
η Efficiency DCDC (VO = 1.2 V) vs Load current / PFM mode Figure 3
η Efficiency DCDC (VO = 1.2 V) vs Load current / PWM mode Figure 4
Line transient response DCDC (PWM) Scope plot for a 3.6 V to 5 V to 3.6 V input voltage change Figure 5
Line transient response DCDC (PFM) Scope plot for a 3.6 V to 5 V to 3.6 V input voltage change Figure 6
Line transient response LDO Scope plot for a 3.6 V to 5 V to 3.6 V input voltage change Figure 7
Load transient response DCDC (PFM) Scope plot for a 10% to 90% load step (40 mA to 360 mA) Figure 8
Load transient response DCDC (PWM) Scope plot for a 10% to 90% load step (40 mA to 360 mA) Figure 9
Load transient response LDO Scope plot for a 10% to 90% load step (20 mA to 180 mA) Figure 10
Startup timing DCDC1, DCDC2, LDO1 and LDO2 Scope plot of startup; R1 = supply voltage is applied Figure 14
LDO POWER SUPPLY REJECTION RATIO (PSRR) Scope plot Figure 11
TPS65708 tc1_lvsae1.gif Figure 1. Efficiency DCDC (VO = 3.3 V) vs Load Current / PFM Mode; for VIN = 3.6 V to 5 V
TPS65708 tc3_lvsae1.gif Figure 3. Efficiency DCDC (VO = 1.2 V) vs Load Current / PFM Mode; for VIN = 3 V to 5 V
TPS65708 tc5_lvsae1.png Figure 5. Line Transient Response DCDC (PWM)
TPS65708 tc7_lvsae1.png Figure 7. Line Transient Response LDO
TPS65708 tc9_lvsae1.png Figure 9. Load Transient Response DCDC (PWM)
TPS65708 tc12_lvsae1.gif
Figure 11. LDO Power Supply Rejection Ratio (PSRR)
TPS65708 tc2_lvsae1.gif Figure 2. Efficiency DCDC (VO = 3.3 V) vs Load Current / PWM Mode; for VIN = 3.6 V to 5 V
TPS65708 tc4_lvsae1.gif Figure 4. Efficiency DCDC (VO = 1.2 V) vs Load Current / PWM Mode; for VIN = 3 V to 5 V
TPS65708 tc6_lvsae1.png Figure 6. Line Transient Response DCDC (PFM)
TPS65708 tc8_lvsae1.png Figure 8. Load Transient Response DCDC (PFM)
TPS65708 tc10_lvsae1.png Figure 10. Load Transient Response LDO