L6731BTR STMicroelectronics, L6731BTR Datasheet - Page 19

• Manufacturer Part Number: L6731BTR
• Description: IC CTRLR ADJ STEP DOWN 16-TSSOP
• Manufacturer: STMicroelectronics

Specifications of L6731BTR

• Applications: Controller, DDR
• Voltage - Input: 1.8 ~ 14 V
• Number Of Outputs: 1
• Voltage - Output: Adjustable down to 0.6V
• Operating Temperature: -40°C ~ 85°C
• Mounting Type: Surface Mount
• Package / Case: 16-TSSOP Exposed Pad, 16-eTSSOP, 16-HTSSOP
• Lead Free Status / RoHS Status: Lead free / RoHS Compliant
• Other names: 497-5099-2

L6731B
6.3
6.4
Figure 11. Compensation Network
Input capacitors
The input capacitors have to sustain the RMS current flowing through them, that is:
Where D is the duty cycle. The equation reaches its maximum value, I
losses in worst case are:
Compensation network
The loop is based on a voltage mode control
internal/external reference voltage and scaled by the external resistor divider. The error
amplifier output V
width modulated (PWM) with an amplitude of V
by the output filter. The modulator transfer function is the small signal transfer function of V
V
and a zero at FESR depending on the output capacitor's ESR. The DC Gain of the modulator is
simply the input voltage V
COMP
. This function has a double pole at frequency F
COMP
is then compared with the oscillator triangular wave to provide a pulse-
IN
divided by the peak-to-peak oscillator voltage: V
Irms
P
ESR
Iout
0 (
5 .
(Figure
D
IN
Iout
1 ( D
at the PHASE node. This waveform is filtered
)
18.). The output voltage is regulated to the
2
LC
)
depending on the L-C
OUT
/2 with D = 0.5. The
OSC
Application details
OUT
.
resonance
19/24
OUT
/