Datasheet

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1 Introduction
The TPS62730 and TPS62733 devices are high-frequency synchronous stepdown dc-dc converters
optimized for ultralow-power wireless applications. The devices are optimized to supply TI’s low-power
wireless sub-1-GHz and 2.4-GHz RF transceivers. The TPS62730 and TPS62733 reduce the current
consumption drawn from the battery during TX and RX modes by a highly efficient stepdown voltage
conversion. They provide up to 100-mA output current and allow the use of tiny and low-cost chip
inductors and capacitors. This devices support most Li-ion primary battery chemistries, with an input range
of 1.9 V to 3.9 V dc.
The TPS62730 and TPS62733 feature an ultralow-power bypass mode with a typical 30-nA current
consumption to support low-power modes of modern RF transceivers. In this bypass mode, the input is
connected to the VOUT pin via an internal 2-Ω bypass FET.
The devices automatically enter bypass mode when the input (battery) voltage falls to the bypass
transition threshold.
2 Considerations With Evaluating the TPS62730 and TPS62733
This part has two modes of operation, the switching buck mode and the dc bypass mode. The IC
automatically shuts down the switcher once the input voltage drops to the bypass threshold, which is a few
millivolts above the regulation voltage. This saves bias power to the switcher.
The user can implement bypass mode at higher input voltages by pulling the ON/BYP pin low. There may
be some applications where the input voltage is too high for the system; exercise caution not to perform
this mode transfer for these cases. Do not leave the ON/BYP pin floating (open), or the IC may be in an
unknown state or mode, and the output voltage may be anywhere between the input voltage and the
regulation voltage.
The EVM has a pullup resistor on the ON/BYP pin to Vin so that it stays in the switching mode if the
jumper is removed and only goes into the bypass mode if the shunt is moved to ground the ON/BYP pin.
This pullup resistor on the EVM loads the input, when in bypass mode, by Vin / 1 MΩ. In a typical
application, a driver controls the ON/BYP pin and does not load the input; thus, do not consider this
current in the quiescent current when in bypass mode.
Also consider (ignore) the pullup resistor for the status output on the EVM when calculating the efficiency
of the converter. The EVM uses a stiff pullup, because loads that may be connected to the STAT pin are
not known. When designing the system, a much higher-value resistor may be appropriate.
3 Performance Specification Summary
SPECIFICATION TEST CONDITIONS MIN TYP MAX UNIT
Input dc voltage, Vin 1.9 3.9 V
Output dc voltage, Vout TPS62730EVM-726, ON/BYP = HIGH and Vin > V
IT BYP
2.1 V
Output dc voltage, Vout TPS62733EVM-726, ON/BYP = HIGH and Vin > V
IT BYP
2.3 V
Output current 0 100 mA
4 Test Summary
The TPS62730EVM-726 and TPS62733EVM-726 boards require an adjustable 4-V, ≥150-mA current-
limited power source to provide input power and a resistive load between 100 Ω and 21 Ω. The test-setup
connections and jumper-setting selections are configured for a stand-alone evaluation, but can be
changed to interface with external hardware such as a system load and microcontroller.
2
TPS62730, TPS62733 Stepdown Converters With Bypass Mode for Ultralow- SLVU455A–April 2011–Revised August 2012
Power Wireless Applications
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