L5973AD STMicroelectronics, L5973AD Datasheet - Page 10

• Manufacturer Part Number: L5973AD
• Description: IC REG SW 2A STEPDOWN 8-SOIC
• Manufacturer: STMicroelectronics
• Type: Step-Down (Buck)r

Specifications of L5973AD

• Internal Switch(s): Yes
• Synchronous Rectifier: No
• Number Of Outputs: 1
• Voltage - Output: 1.24 ~ 35 V
• Current - Output: 2A
• Frequency - Switching: 500kHz
• 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 A
• Input Voltage: 4 V to 36 V
• Switching Frequency: 500 KHz
• Operating Temperature Range: - 40 C to + 150 C
• Mounting Style: SMD/SMT
• Duty Cycle (max): 100 %
• 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
• Other names: 497-1417-5; 497-1417-5; 497-4565-5; E-L5973AD

Functional description
4.5
10/22
Figure 6.
Error amplifier
The voltage error amplifier is the core of the loop regulation. It is a transconductance
operational amplifier whose non inverting input is connected to the internal voltage
reference (1.235 V), while the inverting input (FB) is connected to the external divider or
directly to the output voltage. The output (COMP) is connected to the external compensation
network.
The uncompensated error amplifier has the following characteristics:
Table 5.
The error amplifier output is compared with the oscillator sawtooth to perform PWM control.
Transconductance
Low frequency gain
Minimum sink/source voltage
Output voltage swing
Input bias current
A1/A2=95
Current limitation circuitry
Uncompensated error amplifier
DRIVER
VCC
OUT
I
OFF
PWM
Doc ID 9552 Rev 9
A1
RSENSE
A2
I
1500 μA/300 μA
I
0.4 V/3.65 V
2300 μS
2.5 μA
65 dB
NOT
D00IN1134
RTH
I
L
L5973AD