L6701 STMicroelectronics, L6701 Datasheet - Page 34

• Manufacturer Part Number: L6701
• Description: IC CTRLR 3PH VR10/9/K8 PWRSO-36
• Manufacturer: STMicroelectronics

Specifications of L6701

• Applications: Controller, Intel VR9, VR10, K8
• Voltage - Input: 12V
• Number Of Outputs: 3
• Voltage - Output: 0.8 ~ 1.85 V
• Operating Temperature: 0°C ~ 70°C
• Mounting Type: Surface Mount
• Package / Case: 36-PowerSOIC
• Output Voltage: 0.8 V to 1.85 V
• Output Current: 1.5 A
• Switching Frequency: 110 KHz
• Mounting Style: SMD/SMT
• Maximum Operating Temperature: + 125 C
• Minimum Operating Temperature: 0 C
• Lead Free Status / RoHS Status: Lead free / RoHS Compliant

14 Oscillator
14
Caution:
34/44
Oscillator
The internal oscillator generates the triangular waveform for the PWM charging and
discharging with a constant current an internal capacitor. The switching frequency for each
channel, F
side results in being tripled (300kHz).
The current delivered to the oscillator is typically 25µA (corresponding to the free-running
frequency F
between the OSC pin and SGND. Since the OSC pin is fixed at 1.24V, the frequency is
increased proportionally to the current sunk from the pin considering the internal gain of 4KHz/
µA.
In particular connecting R
relationship:
Maximum programmable switching frequency per phase must be limited to 500kHz to avoid
current reading errors causing, as a consequence, current sharing errors. Anyway, device
power dissipation must be checked prior to design high switching frequency systems.
Figure 16. R
R
OSC
SW
SW
, is internally fixed at 100kHz so that the resulting switching frequency at the load
OSC
vs. SGND
=100kHz) and it may be varied using an external resistor (R
250
200
150
100
50
vs. Switching Frequency
0
100
F
OSC
150
SW
to SGND the frequency is increased according to the following
=
200
100kHz
250
Fsw [kHz] Programmed
+
---------------------------- 4
R
300
1.240V
OSC
(
kΩ
350
)
⋅
400
kHz
---------- -
µA
=
450
100kHz
500
+
OSC
550
----------------------------
R
4.96 10
OSC
) connected
⋅
(
kΩ
6
)
L6701