EVAL6730 STMicroelectronics, EVAL6730 Datasheet - Page 14

• Manufacturer Part Number: EVAL6730
• Description: EVAL BOARD FOR L6730XX
• Manufacturer: STMicroelectronics
• Type: Motor / Motion Controllers & Driversr

Specifications of EVAL6730

• Main Purpose: DC/DC, Step Down
• Outputs And Type: 1, Non-Isolated
• Power - Output: 66W
• Voltage - Output: 3.3V
• Current - Output: 20A
• Voltage - Input: 4.5 ~ 14V
• Regulator Topology: Buck
• Frequency - Switching: 400kHz
• Board Type: Fully Populated
• Utilized Ic / Part: L6730
• Input Voltage: 8 V to 52 V
• Product: Power Management Modules
• Lead Free Status / RoHS Status: Lead free / RoHS Compliant
• For Use With/related Products: L6208
• Other names: 497-5501

Device description
5
5.1
14/52
Device description
Oscillator
The switching frequency is internally fixed to 400 kHz. The internal oscillator generates the
triangular waveform for the PWM charging and discharging an internal capacitor (F
kHz). This current can be varied using an external resistor (R
and GND or V
maintained at fixed voltage (typ. 1.2 V), the frequency is increased (or decreased)
proportionally to the current sunk (sourced) from (into) the pin. In particular by connecting
R
following relationship:
Connecting R
to the following relationship:
Switching frequency variation vs. R
Figure 4.
T
versus GND the frequency is increased (current is sunk from the pin), according to the
Switching frequency variation versus RT
1500
1400
1300
1200
1100
1000
T
CCDR
900
800
700
600
500
400
300
200
100
to V
0
CCDR
in order to change the switching frequency. Since the OSC pin is
Rosc connected to GND
100
reduces the frequency (current is sourced into the pin), according
Fsw
Fsw
200
Doc ID 11938 Rev 3
=
=
400
400
T
300
is shown in
KHz
KHz
+
−
400
Rosc (KOHM)
R
Rosc connected to Vccdr
R
. 9
. 3
OSC
OSC
88
01
(
500
(
Figure
⋅
⋅
K
10
K
10
Ω
Ω
6
7
)
)
600
4.
(1)
(2)
T
700
) connected between OSC pin
800
900 1000
L6730 - L6730B
SW
= 400