Synchronous buck-boost converter

The TPS55165-Q1 output voltage can be set to a fixed level of five or 12V. The TPS55160-Q1 and TPS55162-Q1 devices have a configurable output voltage ranging from 5.7 to 9V that is set by an external resistive divider.

Output currents can be as high as one amp for a normal car battery voltage, and can be maintained at 0.4A for lower input voltages, such as those for common battery-cranking profiles. The buck-boost converter is based on a fixed-frequency, pulse-width-modulation (PWM) control circuit using synchronous rectification to obtain maximum efficiency. The switching frequency is set to 2MHz (typical) which allows for the usage of a small inductor that uses less board space.

A selectable spread-spectrum option (TPS55160-Q1 and TPS55165-Q1) helps reduce radiated electromagnetic interference (EMI). Internal loop compensation eliminates the need for external compensation components. In low-power mode (TPS55160-Q1 and TPS55165-Q1), the device achieves a quiescent current of less than 15µA which allows an automotive electronic control unit (ECU) to stay in standby mode (for example, listen-to-CAN mode) while achieving OEM quiescent-current requirements. The low-power mode can be disabled which forces the converter to operate in full continuous mode at a fixed switching frequency of 2MHz (typical) for the entire load-current range. The maximum average current in the inductor is limited to a typical value of 2A.

The converter can be disabled to minimize battery drain. Furthermore, the device offers a power-good (PG) pin to indicate when the output rail is less than the specified tolerance. The device also has a power-latch function to allow an external microcontroller unit (MCU) to keep the output voltage available for as long as needed.

The device is available in a 20-pin HTSSOP PowerPAD package.

Features

• Qualified for Automotive Applications
• AEC-Q100 Qualified with the Following Results:
  • Device Temperature Grade 1: -40 to +125°C Ambient Operating Temperature
  • Device HBM ESD Classification Level two
  • Device CDM ESD Classification Level C4B
• 2 to 36V Input Voltage Range for V_OUT = 5V
• 5V or 12V Fixed Output Voltage (TPS55165-Q1)
• Adjustable Output Voltage Options from 5.7 to 9V (TPS55160-Q1 and TPS55162-Q1)
• Up to 85% Efficiency
• 1A Output Current for V_OUT = 5V and V_IN ≥ 5.3V
• 0.8A Output Current for V_OUT = 5V and V_IN ≥ 3.8V
• 0.4A Output Current for V_OUT = 5V and V_IN ≥ 2.3V
• Automatic Transition Between Step-Down and Step-Up Mode
• Low-Power Mode for Improved Efficiency at Light Load Conditions (TPS55160-Q1 and 
  TPS55165-Q1)
• Device Quiescent Current Less than 15µA in Low-Power Mode (TPS55160-Q1 and 
  TPS55165-Q1)
• Device Shutdown Current Less than 3µA
• Forced Fixed-Frequency Operation at 2MHz
• Selectable Spread Spectrum (TPS55160-Q1 and TPS55165-Q1)
• Wake-up Through IGN With Power-Latch Function
• Smart Power-Good Output With Configurable Delay Time
• Overtemperature Protection and Output Overvoltage Protection
• Available in Easy-to-Use 20-Pin HTSSOP PowerPAD™ Package

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