L5973D STMicroelectronics, L5973D Datasheet - Page 12

• Manufacturer Part Number: L5973D
• Description: IC REG SWITCHING STEPDOWN SOIC-8
• Manufacturer: STMicroelectronics
• Type: Step-Down (Buck)r

Specifications of L5973D

• Internal Switch(s): Yes
• Synchronous Rectifier: No
• Number Of Outputs: 1
• Voltage - Output: 1.24 ~ 35 V
• Current - Output: 2.5A
• Frequency - Switching: 250kHz
• Voltage - Input: 4 ~ 36 V
• Operating Temperature: -40°C ~ 150°C
• Mounting Type: Surface Mount
• Package / Case: 8-SOIC (3.9mm Width) Exposed Pad, 8-eSOIC. 8-HSOIC
• Power - Output: 2.25W
• Output Voltage: 35 V
• Output Current: 2.5 A
• Input Voltage: 4 V to 36 V
• Switching Frequency: 212 KHz to 280 KHz
• Operating Temperature Range: - 40 C to + 150 C
• Mounting Style: SMD/SMT
• Duty Cycle (max): 100 %
• Current, Input Bias: 2.5 μA
• Current, Output: 300 μA
• Current, Supply: 2.5 mA
• Frequency, Oscillator: 250 kHz
• Package Type: HSOP-8
• Power Dissipation: 2.25 W
• Regulation, Line: 5 mV
• Regulation, Load: 8 mV
• Regulator Type: Low Dropout, Switching
• Temperature, Operating, Range: -40 to +150 °C
• Transconductance: 2.3
• Voltage, Gain: 57 dB
• Voltage, Input: 36 V
• Voltage, Output: 35 V
• Voltage, Output, High: 3.5 V
• Voltage, Output, Low: 0.4 V
• Voltage, Supply: 12 V
• No. Of Pins: 8
• Rohs Compliant: Yes
• Primary Input Voltage: 36V
• No. Of Outputs: 1
• Switching Frequency Max: 250kHz
• Supply Voltage Max: 36V
• Low Dropout Operation: 100 % duty cycle
• For Use With: 497-4134 - EVAL BOARD FOR L5973 SERIES497-4133 - EVAL BOARD FOR L5973 SERIES
• Lead Free Status / RoHS Status: Lead free / RoHS Compliant

Application ideas
12/17
When an output voltage below the internal reference (1.235 V) is required, the circuit
reported in the figure 18 can been used. In this case the minimum voltage reachable is 0.6 V
and can be easily calculated with the following formula:
V
If the load is not present, a resistor connected between V
to avoid that the voltage across C
The value of this resistor has to be calculated taking into account that the current flowing
through this resistance has to be higher than the current flowing through R
Figure 19. Output voltage below the 1.235 V internal voltage reference
OUT
= V
FB
- [(V
REF
- V
FB
)x(R
2
/ R
OUT
1
)]
increases.
OUT
and GND is required in order
2
.
L5973D