The TPS65708 device is a power management unit targeted for embedded camera modules or other portable low-power consumer end equipment. The device contains two high-efficiency step-down converters, two low-dropout linear regulators, and a 7.5-mA current sink for driving a LED. The 2.25-MHz step-down converter enters a low-power mode at light load for maximum efficiency across the widest possible range of load currents. For low-noise applications, the devices can be forced into fixed-frequency PWM mode using the MODE pin. The device allows the use of small inductors and capacitors to achieve a small solution size. The TPS65708 device provides an output current of up to 400 mA on both DC-DC converters and up to 200 mA on each of the LDOs. The enable signal to the DC-DC converters and LDOs is generated internally by the undervoltage lockout circuit.
The TPS65708 comes in a small 16-pin wafer chip-scale package (WCSP) with 0.5-mm ball pitch.
PART NUMBER | PACKAGE | BODY SIZE (NOM) |
---|---|---|
TPS65708 | DSBGA (16) | 2.00 mm × 2.00 mm |
Changes from A Revision (February 2011) to B Revision
Changes from * Revision (October, 2010) to A Revision
PIN | I/O | DESCRIPTION | |
---|---|---|---|
NO. | NAME | ||
A1 | VLDO1 | O | Output voltage from LDO1 |
A2 | VINLDO1 | I | Input voltage pin for LDO1 |
A3 | VINLDO2 | I | Input voltage pin for LDO2 |
A4 | VLDO2 | O | Output voltage from LDO2 |
B1 | ISINK | O | Open-drain current sink; connect to the cathode of a LED |
B2 | PWM | I | Input for LED PWM dimming |
B3 | MODE | I | Set low to enable Power Save Mode. Pulling this PIN to high forces the device to operate in PWM mode over the whole load range. |
B4 | VCC | I | Supply Input for internal reference, has to be connected to VIN1 and VIN2 |
C1 | VIN1 | I | Input voltage pin for buck converter(1) |
C2 | FB1 | I | Feedback input from buck converter(1) |
C3 | FB2 | I | Feedback input from buck converter(2) |
C4 | VIN2 | I | Input voltage pin for buck converter(2) |
D1 | PGND1 | — | Power ground |
D2 | L1 | O | Switch output from buck converter(1) |
D3 | L2 | O | Switch output from buck converter(2) |
D4 | PGND2 | — | Power ground |
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 |
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 |
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 |
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 |
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 |
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 |