The TPS6242x device is a synchronous dual step-down DC–DC converter. It provides two independent output voltage rails powered by 1-cell Li-Ion or 3-cell NiMH/NiCD batteries. The device is also suitable to operate from a standard 3.3-V or 5-V voltage rail.
With an input voltage range of 2.5 V to 6 V, the TPS6242x is ideal for battery-powered portable applications like smart phones, PDAs, and other portable equipment.
With the EasyScale™ serial interface the output voltages can be modified during operation. It therefore supports dynamic voltage scaling for low power DSP and processors.
The TPS6242x operates at 2.25-MHz fixed switching frequency and enter the power-save mode operation at light load currents to maintain high efficiency over the entire load current range. For low-noise applications the devices can be forced into fixed-frequency PWM mode by pulling the MODE/DATA pin High. In the shutdown mode, the current consumption is reduced to 1.2 μA. The device allows the use of small inductors and capacitors to achieve a small solution size.
The TPS6242x operates over a free-air temperature range of –40°C to 85°C. It is available in a 10-pin leadless package (3 mm × 3 mm VSON)
PART NUMBER | PACKAGE | BODY SIZE (NOM) |
---|---|---|
TPS62420 TPS62421 |
VSON (10) | 3.00 mm × 3.00 mm |
Changes from C Revision (June 2010) to D Revision
PART NUMBER | DEFAULT OUTPUT VOLTAGE(1) |
OUTPUT CURRENT |
PACKAGE(2) | ORDERING(3) | PACKAGE MARKING |
|
---|---|---|---|---|---|---|
TPS62420 | OUT1 | Adjustable | 600 mA | DRC | TPS62420DRC | BQF |
OUT2 | 1000 mA | |||||
TPS62421 | OUT1: DEF_1 = Low | 1.2 V | 600 mA | TPS62421DRC | QTQ | |
OUT1: DEF_1 = High | 1.8 V | |||||
OUT2 | 1.8 V | 1000 mA |
PIN | I/O | DESCRIPTION | ||
---|---|---|---|---|
NAME | NO. | |||
ADJ2 | 1 | I | Input to adjust output voltage of converter 2. In adjustable version (TPS62420) connect an external resistor divider between VOUT2, this pin and GND to set output voltage between 0.6 V and VIN. If EasyScale™ interface is used for converter 2, this pin must be directly connected to the output. | |
MODE/DATA | 2 | I | This Pin has 2 functions:
|
|
VIN | 3 | I | Supply voltage, connect to VBAT, 2.5 V to 6 V | |
FB1 | 4 | I | Direct feedback voltage sense input of converter 1, connect directly to VOUT1. An internal feed-forward capacitor is connected between this pin and the error amplifier. In case of fixed output voltage versions or when the interface is used, this pin is connected to an internal resistor divider network. | |
DEF_1 | 5 | I/O | This pin defines the output voltage of converter 1. The pin acts in TPS62420 as an analog input for output voltage setting through external resistors. In fixed default output voltage versions this pin is a digital input to select between two fixed default output voltages, see table ordering information. | |
In TPS62420 an external resistor network needs to be connected to this pin to adjust the default output voltage. | ||||
SW1 | 6 | – | Switch pin of converter 1. Connected to inductor | |
EN1 | 7 | I | Enable input for converter 1, active high | |
GND | 8 | I | GND for both converters, this pin should be connected with the PowerPAD | |
EN2 | 9 | I/O | Enable input for converter 2, active high | |
SW2 | 10 | – | Switch pin of converter 2. Connected to inductor. | |
PowerPAD™ | – | – | Connect to GND |
MIN | MAX | UNIT | |||
---|---|---|---|---|---|
Input voltage on VIN(2) | –0.3 | 7 | V | ||
Voltage on EN, MODE/DATA, DEF_1 | –0.3 | VIN +0.3, ≤7 | V | ||
Maximum current into MODE/DATA | 500 | μA | |||
Voltage on SW1, SW2 | –0.3 | 7 | V | ||
Voltage on ADJ2, FB1 | –0.3 | VIN +0.3, ≤7 | V | ||
TJ(max) | Maximum junction temperature | 150 | °C | ||
TA | Operating ambient temperature | –40 | 85 | °C | |
Tstg | Storage temperature | –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) | ±1000 |
MIN | MAX | UNIT | |||
---|---|---|---|---|---|
VIN | Supply voltage | 2.5 | 6 | V | |
Output voltage range for adjustable voltage | 0.6 | VIN | V | ||
TA | Operating ambient temperature | –40 | 85 | °C | |
TJ | Operating junction temperature | –40 | 125 | °C |
THERMAL METRIC(1) | TPS62420, TPS62421 | UNIT | |
---|---|---|---|
DRC (VSON) | |||
10 PINS | |||
RθJA | Junction-to-ambient thermal resistance | 45.9 | °C/W |
RθJC(top) | Junction-to-case (top) thermal resistance | 64.3 | °C/W |
RθJB | Junction-to-board thermal resistance | 20.4 | °C/W |
ψJT | Junction-to-top characterization parameter | 1.3 | °C/W |
ψJB | Junction-to-board characterization parameter | 20.6 | °C/W |
RθJC(bot) | Junction-to-case (bottom) thermal resistance | 2.8 | °C/W |
PARAMETER | TEST CONDITIONS | MIN | TYP | MAX | UNIT | ||
---|---|---|---|---|---|---|---|
SUPPLY CURRENT | |||||||
VIN | Input voltage range | 2.5 | 6 | V | |||
IQ | Operating quiescent current | One converter, IOUT = 0 mA. PFM mode enabled (Mode = 0) device not switching, EN1 = 1 or EN2 = 1 |
19 | 29 | μA | ||
Two converter, IOUT = 0 mA. PFM mode enabled (Mode = 0) device not switching, EN1 = 1 and EN2 = 1 |
32 | 48 | μA | ||||
IOUT = 0 mA, MODE/DATA = GND, for one converter, VOUT 1.575 V(1) | 23 | μA | |||||
IOUT = 0 mA, MODE/DATA = VIN, for one converter, VOUT 1.575 V(1) | 3.6 | mA | |||||
ISD | Shutdown current | EN1, EN2 = GND, VIN = 3.6 V(2) | 1.2 | 3 | μA | ||
EN1, EN2 = GND, VIN ramped from 0 V to 3.6 V(3) | 0.1 | 1 | |||||
VUVLO | Undervoltage lockout threshold | Falling | 1.5 | 2.35 | V | ||
Rising | 2.4 | ||||||
ENABLE EN1, EN2 | |||||||
VIH | High-level input voltage, EN1, EN2 | 1.2 | VIN | V | |||
VIL | Low-level input voltage, EN1, EN2 | 0 | 0.4 | V | |||
IIN | Input bias current, EN1, EN2 | EN1, EN2 = GND or VIN | 0.05 | 1.0 | μA | ||
DEF_1 INPUT | |||||||
VDEF_1H | DEF_1 high level input voltage | DEF_1 pin is a digital input at fixed output voltage options (TPS62421) | 0.9 | VIN | V | ||
VDEF_1L | DEF_1 low level input voltage | 0 | 0.4 | ||||
IIN | Input biasd current DEF_1 | DEF_1 = GND or VIN | 0.01 | 1 | μA | ||
MODE/DATA | |||||||
VIH | High-level input voltage, MODE/DATA | 1.2 | VIN | V | |||
VIL | Low-level input voltage, MODE/DATA | 0 | 0.4 | V | |||
IIN | Input bias current, MODE/DATA | MODE/DATA = GND or VIN | 0.01 | 1 | μA | ||
VOH | Acknowledge output voltage high | Open-drain, through external pullup resistor | VIN | V | |||
VOL | Acknowledge output voltage low | Open-drain, sink current 500 μA | 0 | 0.4 | V | ||
INTERFACE TIMING | |||||||
tStart | Start time | 2 | μs | ||||
tH_LB | High time low bit, logic 0 detection | Signal level on MODE/DATA pin is > 1.2 V | 2 | 200 | μs | ||
tL_LB | Low time low bit, logic 0 detection | Signal level on MODE/DATA pin < 0.4 V | 2x tH_LB | 400 | μs | ||
tL_HB | Low time high bit, logic 1 detection | Signal level on MODE/DATA pin < 0.4 V | 2 | 200 | μs | ||
tH_LB | High time high bit, logic 1 detection | Signal level on MODE/DATA pin is > 1.2 V | 2x tL_HS | 400 | μs | ||
TEOS | End of Stream | TEOS | 2 | μs | |||
tACKN | Duration of acknowledge condition (MODE/DATE line pulled low by the device) | VIN 2.5 V to 6 V | 400 | 520 | μs | ||
tvalACK | Acknowledge valid time | 2 | μs | ||||
ttimeout | Time-out for entering power-save mode | MODE/DATA pin changes from high to low | 520 | μs | |||
POWER SWITCH | |||||||
RDS(ON) | P-channel MOSFET on-resistance, converter 1, 2 | VIN = VGS = 3.6 V | 280 | 620 | mΩ | ||
ILK_PMOS | P-channel leakage current | VDS = 6 V | 1 | μA | |||
RDS(ON) | N-channel MOSFET on-resistance converter 1, 2 | VIN = VGS = 3.6 V | 200 | 450 | mΩ | ||
ILK_SW1/SW2 | Leakage current into SW1/SW2 pin | Includes N-Chanel leakage current, VIN = open, VSW = 6 V, EN = GND(4) |
6 | 7.5 | μA | ||
ILIMF | Forward current limit PMOS and NMOS | OUT1 600 mA | 2.5 V ≤ VIN ≤ 6 V | 0.85 | 1.0 | 1.15 | A |
OUT2 1000 mA | 1.19 | 1.4 | 1.61 | ||||
TSD | Thermal shutdown | Increasing junction temperature | 150 | °C | |||
Thermal shutdown hysteresis | Decreasing junction temperature | 20 | °C | ||||
OSCILLATOR | |||||||
fSW | Oscillator frequency | 2.5 V ≤ VIN ≤ 6 V | 2.0 | 2.25 | 2.5 | MHz | |
OUTPUT | |||||||
VOUT | Adjustable output voltage range | 0.6 | VIN | V | |||
Vref | Reference voltage | 600 | mV | ||||
VOUT (PFM) | DC output voltage accuracy PFM mode, adjustable and fixed output voltage(6) | Voltage positioning active, MODE/DATA = GND, device operating in PFM mode, VIN = 2.5 V to 5 V (5)(7) |
–1.5% | 1.01 × VOUT | 2.5% | ||
VOUT | MODE/DATA = GND; device operating in PWM mode VIN = 2.5 V to 6 V(7) | –1% | 0% | 1% | |||
VIN = 2.5 V to 6 V, Mode/Data = VIN , Fixed PWM operation, 0 mA < IOUT < IOUTMAX(8) | –1% | 0% | 1% | ||||
DC output voltage load regulation | PWM operation mode | 0.5 | %/A | ||||
tStart up | Start-up time | Activation time to start switching(9) | 170 | μs | |||
tRamp | VOUT Ramp UP time | Time to ramp from 5% to 95% of VOUT | 750 | μs |
PACKAGE | RθJA | POWER RATING FOR TA ≤ 25°C | DERATING FACTOR ABOVE TA = 25°C |
---|---|---|---|
DRC | 49°C/W | 2050 mW | 21 mW/°C |