Texas Instruments TPS2145

Adjustable LDO + Dual Switch For USB DSP And Portable Applications Active-Low Enables

Two power-distribution switches and an adjustable (TPS2145) or fixed (TPS2147) LDO are incorporated in one small package, providing a power management solution that saves up to 60% in board space over typical implementations. Designed to meet USB 2.0 bus-powered hub requirements, these devices also allow core and I/O voltage sequencing in DSP applications, or power segmentation in portable equipment. Each current-limited switch is a 340-m N-channel MOSFET capable of supplying 200 mA of continuous current. A logic enable compatible with 5-V logic and 3-V logic controls each MOSFET as well as the LDO in the TPS2145. The internal charge pump provides the gate drive controlling the power-switch rise times and fall times, minimizing current surges during switching. The charge pump requires no external components. The LDO has a drop-out voltage of only 0.35 V and with the independent enable on the TPS2145 LDO, the LDO can be used as an additional switch. The LDO output range for the TPS2145 is 1 V to 3.3 V, while the TPS2147 is fixed at 3.3 V. The TPS2145 and TPS2147 have active-low switch enables and the TPS2155 and TPS2157 have active-high switch enables.