SBOA212A January 2018 – January 2019 OPA2353 , OPA2365 , OPA353 , OPA365 , TLV3502
Design Goals
Input | Output | Supply | ||||
---|---|---|---|---|---|---|
ViMin | ViMax | VoMin | VoMax | Vcc | Vee | Vref |
–2.0 V | 2.0 V | 0 V | 5 V | 5 V | 0 V | 2.5 V |
Design Description
This circuit utilizes a triangle wave generator and comparator to generate a 500 kHz pulse-width-modulated (PWM) waveform with a duty cycle that is inversely proportional to the input voltage. An op amp and comparator (U3 and U4) generate a triangle waveform which is applied to the inverting input of a second comparator (U2). The input voltage is applied to the non-inverting input of U2. By comparing the input waveform to the triangle wave, a PWM waveform is produced. U2 is placed in the feedback loop of an error amplifier (U1) to improve the accuracy and linearity of the output waveform.
Design Notes
Design Steps
Design Simulations
DC Simulation Results
Transient Simulation Results
Design References
See Analog Engineer's Circuit Cookbooks for TI's comprehensive circuit library.
See circuit SPICE simulation file SBOC502.
See TIPD108, Analog PWM Generator 5V, 500 kHz PWM Output
Design Featured Op Amp
OPA2365 | |
---|---|
Vss | 2.2 V to 5.5 V |
VinCM | Rail-to-rail |
Vout | Rail-to-rail |
Vos | 100 µV |
Iq | 4.6 mA |
Ib | 2 pA |
UGBW | 50 MHz |
SR | 25 V/µs |
#Channels | 2 |
OPA2365 |
Design Comparator
TLV3502 | |
---|---|
Vss | 2.2 V to 5.5 V |
VinCM | Rail-to-rail |
Vout | Rail-to-rail |
Vos | 1 mV |
Iq | 3.2 mA |
Ib | 2 pA |
UGBW | — |
SR | — |
#Channels | 2 |
TLV3502 |
Design Alternate Op Amp
OPA2353 | |
---|---|
Vss | 2.7 V to 5.5 V |
VinCM | Rail-to-rail |
Vout | Rail-to-rail |
Vos | 3 mV |
Iq | 5.2 mA |
Ib | 0.5 pA |
UGBW | 44 MHz |
SR | 22 V/µs |
#Channels | 2 |
OPA2352 |