CN103152915A - Switching type four-section light emitting diode (LED) illumination regulation control circuit - Google Patents

Abstract

The invention discloses a switching type four-section light emitting diode (LED) illumination regulation control circuit, and relates to electronic technology. The switching type four-section LED illumination regulation control circuit is composed of a counter module, a latch module and a state machine module. The counter module is composed of a first D flip-flop (DFF) and a second DFF. The latch module is composed of a third DFF. The state machine module is composed of a fourth DFF and a fifth DFF. Compared with a traditional control module, the switching type four-section LED illumination regulation control circuit is simple in structure, stable and reliable in performance, saved in chip area and capable of reducing chip cost.

Description

Four sections LED adjusting control circuits of switching regulator

Technical field

The present invention relates to electronic technology, particularly integrated circuit technique.

Background technology

As a kind of light source, light modulation is very important.The purpose of light modulation not only obtains a more comfortable environment between two parties in order to be in, and can reduce unnecessary electric light line, thereby realizes the purpose of energy-saving and emission-reduction, this in the situation that the world wide shortage of resources have important practical significance.The mode of LED light modulation at present is a lot, comprises linearity light adjusting, TRIAC light modulation, PWM light modulation etc.These dimming modes cut both ways, and are applied to different occasions.

Summary of the invention

Technical problem to be solved by this invention is that a kind of adjusting control circuit that utilizes the brightness of the sectional-regulated LED light source of external switch number of times is provided.

The technical scheme that the present invention solve the technical problem employing is, four sections LED adjusting control circuits of switching regulator are made of counter module, latch module and state machine module,

Counter module is comprised of the first d type flip flop DFF1 and the second d type flip flop DFF2, the CLK termination clock signal of the first d type flip flop, the CLK end of Q termination the second d type flip flop DFF2, D termination _ Q end, R termination external switch detection signal; The CLK end of the Q termination 3d flip-flop DFF3 of the second d type flip flop DFF2, D termination _ Q end, R termination external switch detection signal;

The latch module is made of 3d flip-flop DFF3, the CLK end of _ Q termination four d flip-flop DFF4, D termination high level VDD, R termination external switch detection signal;

State machine module is made of four d flip-flop DFF4 and the 5th d type flip flop DFF5, the CLK of Q termination the 5th d type flip flop DFF5 of four d flip-flop DFF4 end, the D end and _ Q termination the first output Q0, R termination power-on reset signal; The D of the 5th d type flip flop DFF5 end and _ Q termination the second output Q1, R termination power-on reset signal.

The invention has the beneficial effects as follows, the present invention compares with traditional control module, and circuit structure is simple, and is stable and reliable for performance, saves chip area, reduces chip cost.Because traditional testing circuit directly detects from full wave rectified signal, cycle is longer, the gate time of internal counter will be long, cause Counter Design complicated, take very large chip area, and this control circuit coordinates novel detection mode, can make light modulation partly become very simple and reliable, greatly saves the cost of chip.

Description of drawings

Fig. 1 is module map of the present invention.

Fig. 2 is circuit structure diagram of the present invention.In figure, VDD and GND are respectively VDD-to-VSS; CLK is clock signal; POR is power-on reset signal; SWDETEC is the external switch detection signal.

Embodiment

Referring to Fig. 1,2.Four sections LED adjusting control circuits of switching regulator are made of counter module, latch module and state machine module,

Counter module is comprised of the first d type flip flop DFF1 and the second d type flip flop DFF2, the CLK termination clock signal of the first d type flip flop, the CLK end of Q termination the second d type flip flop DFF2, D termination _ Q end, R termination external switch detection signal; The CLK end of the Q termination 3d flip-flop DFF3 of the second d type flip flop DFF2, D termination _ Q end, R termination external switch detection signal;

The latch module is made of 3d flip-flop DFF3, the CLK end of _ Q termination four d flip-flop DFF4, D termination high level VDD, R termination external switch detection signal;

State machine module is made of four d flip-flop DFF4 and the 5th d type flip flop DFF5, the CLK of Q termination the 5th d type flip flop DFF5 of four d flip-flop DFF4 end, the D end and _ Q termination the first output Q0, R termination power-on reset signal; The D of the 5th d type flip flop DFF5 end and _ Q termination the second output Q1, R termination power-on reset signal.

The specific works process is as follows: add the 5V supply voltage at the VDD-to-VSS end, the POR end can produce an electrification reset low pulse signal resets state machine, then the CLK end can produce the clock signal of a 40KHz, if this moment, external switch was in closure state always, the SWDETEC end low level can occur within each clock cycle, thereby counter is constantly resetted, and output _ the Q of latch remains high level always, and the state of state machine can remain 11; If external switch is opened, when namely being in dimming state, the SWDETEC end can keep high level always, and this moment, state machine began counting, when after continuous four clock cycle, the SWDETEC end is still high level, and the state of latch can change, thereby makes the state of state machine become 10 by 11, if after this SWDETEC still remains height, counter is counted again, but the state that has latched can remain unchanged, thereby the state of state machine is remained unchanged; If after this external switch is again closed, the SWDETEC end produces a low level in each clock cycle again, make the state turnover of latch, but the state of state machine can't change; If after this switch repeats open closed, can repeat former process, make the state of state machine become 01 by 10, become 00 by 01, become 11 by 00.And one of four states is distinguished four ranks of corresponding LED brightness, thereby completes the realization of four sections light modulations of LED.

Claims (1)

1. four sections LED adjusting control circuits of switching regulator, is characterized in that, consisted of by counter module, latch module and state machine module,

Counter module is comprised of the first d type flip flop DFF1 and the second d type flip flop DFF2, the CLK termination clock signal of the first d type flip flop, the CLK end of Q termination the second d type flip flop DFF2, D termination _ Q end, R termination external switch detection signal; The CLK end of the Q termination 3d flip-flop DFF3 of the second d type flip flop DFF2, D termination _ Q end, R termination external switch detection signal;

The latch module is made of 3d flip-flop DFF3, the CLK end of _ Q termination four d flip-flop DFF4, D termination high level VDD, R termination external switch detection signal;

State machine module is made of four d flip-flop DFF4 and the 5th d type flip flop DFF5, the CLK of Q termination the 5th d type flip flop DFF5 of four d flip-flop DFF4 end, the D end and _ Q termination the first output Q0, R termination power-on reset signal; The D of the 5th d type flip flop DFF5 end and _ Q termination the second output Q1, R termination power-on reset signal.

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