EVAL5970D STMicroelectronics, EVAL5970D Datasheet - Page 6

• Manufacturer Part Number: EVAL5970D
• Description: EVAL BOARD FOR L5970 SERIES
• Manufacturer: STMicroelectronics
• Type: DC/DC Switching Converters, Regulators & Controllersr

Specifications of EVAL5970D

• Main Purpose: DC/DC, Step Down
• Outputs And Type: 1, Non-Isolated
• Voltage - Output: 1.235 ~ 35V
• Current - Output: 1A
• Voltage - Input: 4.4 ~ 36V
• Regulator Topology: Buck
• Frequency - Switching: 250kHz
• Board Type: Fully Populated
• Utilized Ic / Part: L5970
• Input Voltage: 4.4 V to 36 V
• Output Voltage: 1.2 V to 35 V
• Dimensions: 42 mm x 34 mm
• Product: Power Management Modules
• Lead Free Status / RoHS Status: Contains lead / RoHS non-compliant
• Power - Output: -
• Lead Free Status / Rohs Status: Lead free / RoHS Compliant
• For Use With/related Products: L5970D
• Other names: 497-4132

Functional description
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2.1
2.2
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Functional description
The main internal blocks are shown in the device block diagram in
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Power supply and voltage reference
The internal regulator circuit (shown in
voltage Preregulator, the Bandgap voltage reference and the Bias block that provides
current to all the blocks. The Starter gives the start-up currents to the entire device when the
input voltage goes high and the device is enabled (inhibit pin connected to ground). The
Preregulator block supplies the Bandgap cell with a preregulated voltage V
very low supply voltage noise sensitivity.
Voltages monitor
An internal block continuously senses the V
their thresholds, the regulator begins operating. There is also a hysteresis on the V
(UVLO).
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 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 modulation (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.
Figure
CC
, V
5) consists of a start-up circuit, an internal
REF
and V
BG
. If the voltages go higher than
Figure
4. They are:
REG
that has a
CC
AN1330