Texas Instruments' PTN78 series wide-input, non-isolated power modules simplify power management designs in security cameras. The diagram in the Overview tab shows a typical power management circuit that is powered by a wall-mount AC/DC adapter. A 24V battery is used to provide emergency backup power. Due to the wide output voltage tolerance of the 24V from the AC/DC adapter, the circuit requires DC/DC modules capable of operating over a wide input voltage range.
The flexible PTN78000, PTN78060 and PTN78020 series of 1.5A, 3A and 6A devices can be used in a wide variety of applications that require input voltages from 7V to 36V. The modules are lead (Pb)-free, and RoHS-compliant, and provide a precisely regulated output voltage that is adjustable via an external resistor. Providing excellent line and load regulation, the modules deliver efficiencies of up to 96%.
PTN78 series modules provide a single regulated output over a wide input voltage range. The modules in this diagram are shown operating from a 24V input. One module provides a 12V output to a motor control circuit for the camera's focus and zoom functions. The other module provides a 3.3V output to a video amplifier and a PTH04070W non-isolated module, which produces a 1.2V output for a DSP's core voltage.
3A, 3.3V/5V Input Adjustable Switching Regulator
The PTH04070W is a highly integrated, low-cost switching regulator module that delivers up to 3A of output current. Occupying less PCB area than a standard TO-220 linear regulator IC, the PTH04070W provides output current at a much higher efficiency and with much less power dissipation, thereby eliminating the need for a heat sink. Their small size (0.5in x 0.4in), high efficiency, and low cost make these modules attractive for a variety of applications.
- Up to 3A output current at 85°C
- 3.3V/5V input voltage and wide-output voltage adjust (0.9V to 3.6V)
- 160 W/in3 power density
- Efficiencies up to 94%
- On/Off inhibit
- Undervoltage lockout (UVLO)
- Output overcurrent protection (nonlatching, auto-reset)
- Overtemperature protection
- Ambient temperature range: -40°C to 85°C