T2117 查看數據表（PDF） - Atmel Corporation

零件编号

产品描述 (功能)

生产厂家

T2117

Zero-voltage Switch with Adjustable Ramp

Atmel Corporation 

4. Triac Firing Current (Pulse)

This depends on the triac requirement. It can be limited by the gate series resistance which is

calculated as follows:

RGmax ≈

7----.--5----V------–-----V----G---m----a---x- – 36 Ω

IGmax

IP

=

-I-G----m----a--x-

T

×

tp

where:

VG = Gate voltage

IGmax = Maximum gate current

Ip = Average gate current

tp = Firing pulse width

T = Mains period duration

5. Firing Pulse Width tp

This depends on the latching current of the triac and its load current. The firing pulse width is

determined by the zero-crossing detection which can be influenced by the synchronous resis-

tance, Rsync, (see Figure 5-2 on page 5).

tp

=

2-ω-

arc.

sin

⎛

⎝

-I-L--P--×------V-2---M---⎠⎞

where

IL = Latching current of the triac

VM = Mains supply, effective

P = Load power

The total current consumption is influenced by the firing pulse width which can be calculated as

follows:

Rsync

=

V-----M--------2------s---i-n----⎝⎛--ω-----×------t-2---p---⎠⎞----–-----0---.--6-----V--

3.5 × 10-5A

– 49 kΩ

4 T2117

4768B–INDCO–10/05

Share Link: