L6722TR STMicroelectronics, L6722TR Datasheet - Page 13

• Manufacturer Part Number: L6722TR
• Description: IC BUCK ADJ 2A TRPL 36VFQFPN
• Manufacturer: STMicroelectronics
• Type: Step-Down (Buck)r

Specifications of L6722TR

• Internal Switch(s): No
• Synchronous Rectifier: No
• Number Of Outputs: 3
• Voltage - Output: Adj to 0.8V
• Current - Output: 2A
• Frequency - Switching: 100kHz
• Voltage - Input: 12V
• Operating Temperature: 0°C ~ 70°C
• Mounting Type: Surface Mount
• Package / Case: 36-VFQFN, 36-VFQFPN
• Power - Output: 3.5W
• Operating Temperature Range: - 40 C to + 125 C
• Mounting Style: SMD/SMT
• Lead Free Status / RoHS Status: Lead free / RoHS Compliant
• Other names: 497-5904-2

L6722
4
Device description
L6722 is multi-phase PWM controller with embedded high current drivers that provides
complete control logic and protections for a high performance step-down DC-DC voltage
regulator. Multi-phase buck is the simplest and most cost-effective topology employable to
satisfy the increasing current demand of the modern high current DC/DC converters and POLs
requirements. It allows distributing equally load and power between the phases using smaller,
cheaper and most common external power mosfets and inductors. Moreover, thanks to the
equal phase-shift between each phase, the input and output capacitor count results in being
reduced. Phase interleaving causes in fact input rms current and output ripple voltage reduction
and show an effective output switching frequency increase: the 100kHz free-running frequency
per phase, externally adjustable through a resistor, results multiplied on the output by the
number of phases.
The device comes with a fixed 0.8V reference that guarantee the output regulated voltage to be
within
FBG. OFFSET may be added to the main reference so allowing the device to be tested for
margining during the system production. In addition, droop function may be enabled to perform
precise voltage positioning according to the delivered current.
SS is performed by increasing the reference in 2048 clock cycles in closed loop regulation.
L6722 provides a complete set of protections to avoid damaging the load in any operative and
non-operative conditions:
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A compact VFQFPN36 package with exposed thermal pad allows dissipating the power to drive
the external mosfet through the system board.
Over-Voltage protection protects the load from dangerous over stress latching immediately
the lower driver ON and driving high the FAULT pin.
Preliminary OVP protection also allows the device to protect the load from dangerous OVP
when VCC is not above the UVLO threshold.
UVP protection latches the device and drives high the FAULT pin.
Over-Current protection is provided with an OC threshold for each phase; when set, it
causes the device to enter in constant current mode until the latched UVP.
Low-Side-Less start-up allows the device to perform soft-start over pre-biased output
avoiding dangerous current return through the main inductors as well as negative spike at
the load side and allowing the device to work in redundant systems.
±
1
%
; the output voltage is then adjustable through a resistor divider between FBR and
4 Device description
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