Overview
The TPS2421-1DDAR, produced by Texas Instruments, is a highly integrated hot swap power management device designed to provide superior protection and control in various applications. This device is particularly suited for systems where the load is powered by busses up to 20 V, including standard bus voltages as low as 3.3 V. It features multiple programmable protection mechanisms, including a non-current limiting fault threshold, a hard current limit, and a fault timer. The TPS2421-1DDAR is available in an 8-pin PowerPad™ SO-8 package, making it easy to integrate into a wide range of systems.
Key Specifications
| Parameter | Description | Value |
|---|---|---|
| Package | HSOP (8-pin PowerPad™ SO-8) | 4.89 mm × 3.90 mm |
| Input Voltage Range | Recommended operating voltage range | 3 V to 20 V |
| Current Limit | Internally set at 150% of the fault current (ISET) | Programmable via ISET pin |
| Fault Timer | Set by capacitor connected from CT to GND | Charges at 35 μA, discharges at 40 μA and 1.4 μA |
| Operating Temperature Range | Junction temperature range | -50°C to 150°C |
| Protection Features | Overload, overcurrent, thermal shutdown, SOA protection | Multiple programmable protection features |
| Enable Pin | Device enabled when pulled low | Hysteretic input threshold |
Key Features
- Programmable Protection: The device features a non-current limiting fault threshold, a hard current limit, and a fault timer, providing comprehensive protection against various fault conditions.
- Hot Swap MOSFET Protection: Power limit circuitry protects the internal MOSFET against SOA (Safe Operating Area) related failures.
- Flexible Operation: Available in latch-off on fault (TPS2421-1) and retry on fault (TPS2421-2) configurations.
- Low Startup Voltage: Supports startup into loads as low as 3 V, with a maximum UV turn-on threshold of 2.9 V.
- Fault Indicator: Open-drain output (FLT) indicates fault conditions such as overload or thermal shutdown.
Applications
- RAID Arrays: Protects and manages power in RAID storage systems.
- Telecommunications: Used in telecom equipment for reliable power management.
- Plug-In Circuit Boards: Ideal for hot-swappable circuit boards.
- Disk Drives and SSDs: Manages power and protects disk drives and solid-state drives during startup and operation.
- PCIe and Fan Control: Suitable for PCIe cards and fan control systems requiring robust power management.
Q & A
- What is the primary function of the TPS2421-1DDAR device?
The TPS2421-1DDAR is a highly integrated hot swap power management device that provides superior protection and control in applications where the load is powered by busses up to 20 V.
- What are the key protection features of the TPS2421-1DDAR?
The device features a non-current limiting fault threshold, a hard current limit, a fault timer, and hot swap MOSFET protection against SOA related failures.
- How is the fault timer set in the TPS2421-1DDAR?
The fault timer is set by connecting a capacitor from the CT pin to GND. The capacitor charges at 35 μA and discharges at 40 μA and 1.4 μA.
- What are the different configurations available for the TPS2421 device?
The TPS2421 is available in latch-off on fault (TPS2421-1) and retry on fault (TPS2421-2) configurations.
- What is the recommended operating voltage range for the TPS2421-1DDAR?
The recommended operating voltage range is 3 V to 20 V.
- How does the FLT pin indicate fault conditions?
The FLT pin is an open-drain output that pulls low on any condition that causes the output to open, such as an overload with a fault time-out or a thermal shutdown.
- What types of applications is the TPS2421-1DDAR suitable for?
The device is suitable for RAID arrays, telecommunications, plug-in circuit boards, disk drives, SSDs, PCIe, and fan control systems.
- How does the device handle hard overloads?
When a hard overload occurs, the device immediately shuts off current to the load without waiting for the fault timer to expire and then attempts to restart.
- What is the purpose of the EN pin?
The EN pin enables the device when pulled low, with a hysteretic input threshold allowing for startup delay programming with an external RC circuit.
- How is the current limit set in the TPS2421-1DDAR?
The current limit is set by a resistor connected from the ISET pin to GND, with the current limit internally set at 150% of the fault current (ISET).
