RT6310CSLASHCH datasheet(12/54 Pages) RICHTEK

12 / 54 page

RT6310

is a registered trademark of Richtek Technology Corporation.

www.richtek.com

DS6310-04

August 2023

EN/MODE Input Current vs. EN/MODE Input Voltage

EN/MODE Input Voltage (V)

VIN = 12V

EN/MODE Sink Current

The RT6310 does not allow uncertain voltage on

EN/MODE pin, which may cause the logic or behavior

error on device. In order to prevent the EN/MODE pin

from floating, the RT6310 builds the EN/MODE input

current for eliminating floating voltage on EN/MODE pin.

The characteristic of EN/MODE input current vs

EN/MODE input voltage is shown in Figure 3.

Figure 3. Characteristics of EN/MODE Input Current

Soft-Start

The RT6310 provides an internal soft-start to prevent

large input inrush current and output voltage overshoot.

If EN/MODE voltage and input voltage exceed their

rising thresholds, the soft-start function is activated. The

VFB starts to track the internal reference voltage ranging

from zero to the target.

Valley Current-Limit Setting

The RT6310A/AH/D/DH provides valley current-limit

setting pin to adjust current-limit level. When both "VIN

rises to its UVLO rising threshold" and "EN/MODE is

activated" are satisfied and kept for 600

s, the RT6310

determines and locks the current-limit level according to

the voltage on the ILMT pin. Beside the previous

described timing behavior, any change of valley current-

limit status is invalid. The valley current-limit setting level

is selected as follows :

RT6310A/AH

⚫

13A : Connect ILMT pin to PGND.

⚫

15A : Leave ILMT pin floating/open.

⚫

17A : Connect ILMT pin to 5V.

RT6310D/DH

⚫

6.5A : Connect ILMT pin to PGND.

⚫

16A : Leave ILMT pin floating/open.

⚫

25.8A : Connect ILMT pin to 5V.

Valley Current Limit

The RT6310 features a cycle-by-cycle valley current

limit for avoiding the large output current and overheat.

The device cycle-by-cycle compares the valley current

of the inductor with the valley current-limit threshold.

The output current is limited to the sum of the valley

current and a half of ripple current when valley current

of inductor reaches valley current-limit threshold.

After the device completes the minimum off-time and

keeps ON state of low-side MOSFET, the inductor

valley current level is monitored by measuring the low-

side MOSFET voltage between the LX pin and PGND

pin during the ON state of low-side MOSFET. During the

ON state of low-side MOSFET, the measured low-side

MOSFET voltage is proportional to the low-side

MOSFET current. In order to improve the accuracy of

measured current, the temperature compensation

circuit is built internally.

In order to prevent the device from over current, if the

measured low-side MOSFET current is higher than

valley current-limit threshold, the device remains ON

state of the low-side MOSFET and the one-shot on-time

timer is inhibited until its current linearly decreases

lower than valley current-limit threshold. Once the low-

side MOSFET current is below valley current-limit

threshold, the next one-shot on-time timer is permitted

to generate. The circuit of the cycle-by-cycle valley

current limit works in every switching cycle.

Peak Current Limit

The RT6310 with a cycle-by-cycle peak current limit

prevents the device from inductor saturation or any

possibility of damage caused by too much output inrush

current. The device cycle-by-cycle compares the peak

current of the inductor with the peak current-limit

threshold.

After the device finishes the minimum on-time timer and

remains ON state of high-side MOSFET, the inductor

peak current level is monitored by sensing the high-side

MOSFET voltage between the VIN pin and LX pin

RT6310C/CH 数据表(PDF) 12 Page - Richtek Technology Corporation

RT6310C/CH 数据表(HTML) 12 Page - Richtek Technology Corporation

Html Pages

1 2 3 4 5 6 7 8 9 10 11 12 13 14 15 16 17 18 19 20 21 22 23 24 25 26 27 28 29 30 31 32 33 34 35 36 37 38 39 40 41 42 43 44 45 46 47 48 49 50 51 52 53 54

数据表下载