A5975ADTR STMicroelectronics, A5975ADTR Datasheet - Page 11

• Manufacturer Part Number: A5975ADTR
• Description: IC REG SW STEP-DOWN 2.5A 8SOIC
• Manufacturer: STMicroelectronics
• Series: -r
• Type: Step-Down (Buck), PWMr

Specifications of A5975ADTR

• Internal Switch(s): Yes
• Synchronous Rectifier: No
• Number Of Outputs: 1
• Voltage - Output: 1.235 V ~ 35 V
• Current - Output: 2.5A
• Frequency - Switching: 500kHz
• Voltage - Input: 4 V ~ 36 V
• Operating Temperature: -40°C ~ 125°C
• Mounting Type: Surface Mount
• Package / Case: 8-SOIC (0.154", 3.90mm Width) Exposed Pad
• Lead Free Status / Rohs Status: Lead free / RoHS Compliant
• Other names: 497-11425-2

A5975AD
5
Figure 3.
Functional description
The main internal blocks are shown in the device block diagram in
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Block diagram
A voltage regulator supplying the internal circuitry. From this regulator, a 3.3 V
reference voltage is externally available.
A voltage monitor circuit which checks the input and the internal voltages.
A fully integrated sawtooth oscillator with a frequency of 500 kHz ± 15%, including also
the voltage feed-forward function and an input/output synchronization pin.
Two embedded current limitation circuits which control the current that flows through
the power switch. The pulse-by-pulse current limit forces the power switch off cycle-by-
cycle if the current reaches an internal threshold, while the frequency shifter reduces
the switching frequency in order to significantly reduce the duty cycle.
A transconductance error amplifier.
A pulse width modulator (PWM) comparator and the relative logic circuitry necessary to
drive the internal power.
A high side driver for the internal P-MOS switch.
An inhibit block for standby operation.
A circuit to implement the thermal protection function.
Doc ID 018761 Rev 1
Figure
Functional description
3. They are:
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