The MP5507E utilizes MPS' patented energy storage and release management technology, which minimizes the required storage components, system solution size, and cost.
The MP5507E power management chip boosts the input voltage to a higher storage voltage under normal conditions and releases energy into the system in the event of an input interruption.
An internal input current limiting module with DVDT control prevents inrush current during system power-up and provides reverse current blocking during backup.
The slope of the system voltage power-up change is programmable. Both the storage and release voltages are programmable for different system applications. The MP5507E power management chip minimizes the use of existing standard external components and is packaged in a QFN-16 (2.5mm x 3.2mm) package.
The MP5507E provides a very compact and efficient power backup solution for typical solid-state drive applications. MPS' patented lossless energy storage and release management circuitry uses a bidirectional buck/boost converter to achieve optimal energy transfer and provide a cost-effective energy storage solution.
When the system powers on, the MP5507E power management chip's built-in boost converter charges the large-capacity storage capacitor to the programming voltage. In the event of an input power interruption, the MP5507E indicates a VB bus power failure, disconnects the input switch, and transfers energy from the storage capacitor to VB via its built-in buck converter. During system operation, it maintains the bus voltage at a stable level, consuming energy for data backup. The buck converter can operate at 100% duty cycle to completely deplete the stored energy. Depending on the required power standby time and the storage components used in different applications, the MP5507E can provide a compact solution with programmable storage voltage settings.
During VIN startup, the VB bus voltage charges from 0 to VIN. The rise rate of VB is controlled by the DVDT capacitor. This function prevents input inrush current and provides protection for downstream systems.
The EHCH is used to enable and disable the storage charge and release circuitry. The storage charge circuitry has two modes: pre-charge mode (using a current source to charge the STRG voltage from 0V to VB) and boost mode (charging the STRG voltage to set the voltage). Pre-charge mode uses a near-constant current source (approximately 130mA) to charge the STRG voltage to VB. Boost mode is activated when the STRG voltage approaches VB and the VB voltage exceeds a certain threshold (PGB rises).
If ENCH is already high before VIN rises to the UVLO threshold, the storage charging circuit will automatically begin linear charging when VIN exceeds the UVLO threshold (typically 2.5V). When the storage voltage is charged to near VB, it switches to boost switching mode, and PGB rises. If ENCH rises after VB, DVDT passes and PGB rises, then pre-charging begins, followed by boost switching.
Because the release mode is triggered when the FBB voltage is below 0.79V (although there is a 23mV hysteresis between boost mode and release mode), the VB voltage may be pulled back low and unexpectedly enter release mode. To avoid this, if system I/O is available to control ENCH, enable ENCH after VB stabilizes.
After the storage voltage is charged, the internal boost converter automatically adjusts it to a stable voltage. The MP5507E power management chip uses burst mode to minimize converter power loss. When the storage voltage drops below a set voltage, burst mode is activated and the storage capacitor is charged. During the burst, the current limit and low-side MOSFET (LS-FET) control switch are activated. When the LS-FET is turned on, the inductor current increases until it reaches the current limit (approximately 500mA). After the current limit is reached, the LS-FET will turn off for a set minimum off time. At the end of this minimum off time, if the feedback voltage remains below the internal reference voltage of 0.79V, the LS-FET will turn on again. Otherwise, the MP5507E waits until the voltage drops below the threshold before turning the LS-FET back on. In boost mode, the HS-FET is off, and the body diode of the HS-FET conducts current.
