A5975DTR STMicroelectronics, A5975DTR Datasheet - Page 11

• Manufacturer Part Number: A5975DTR
• Description: IC REG SW STEP-DOWN 3A 8SOIC
• Manufacturer: STMicroelectronics
• Series: -r
• Type: Step-Down (Buck), PWMr

Specifications of A5975DTR

• Internal Switch(s): Yes
• Synchronous Rectifier: No
• Number Of Outputs: 1
• Voltage - Output: 1.235 V ~ 35 V
• Current - Output: 3A
• Frequency - Switching: 250kHz
• 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: 497-11426-2

A5975D
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 250 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 018760 Rev 1
Figure
Functional description
3. They are:
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