SGLS247C September 2011 – December 2025 TPS763-Q1
PRODUCTION DATA
The TPS763xx-Q1 is designed to work with an output capacitor connected between OUT and GND to stabilize the internal loop control. The minimum recommended capacitance value is 4.7μF and the ESR (equivalent series resistance) must be between 0.3Ω and 10Ω. Capacitor values of 4.7μF or larger are acceptable, provided the ESR is less than 10Ω. Solid tantalum electrolytic, aluminum electrolytic, and multilayer ceramic capacitors are all good choice for the stable operation, provided these capacitors meet the requirements described above.
One disadvantage of ceramic capacitors is that the capacitance varies with temperature. Most large-value ceramic capacitors (≥ 2.2µF) are manufactured with the Z5U or Y5V temperature characteristic. Thus, resulting in the capacitance dropping by more than 50% as the temperature goes from 25°C to 85°C.
This capacitance drop potentially cause problems if a 4.7µF capacitor is used on the output because that capacitor goes down to approximately 4.7µF at high ambient temperatures. Such low capacitance causes the TPS763xx-Q1 to oscillate. If Z5U or Y5V capacitors are used on the output, adhere to a minimum capacitance value of 4.7µF.
A better choice for temperature coefficient in ceramic capacitors is X7R, which holds the capacitance within ±15%. Unfortunately, the larger values of capacitance are not offered by all manufacturers in the X7R dielectric.
Tantalum capacitors are less desirable than ceramics for use as output capacitors. These components are more expensive when comparing equivalent capacitance and voltage ratings in the 1µF to 4.7µF range.
Another important consideration is that tantalum capacitors have higher ESR values than equivalent size ceramics. Which means that although a tantalum capacitor potentially has an ESR value within the stable range, the capacitor is larger in capacitance. Thus, the tantalum capacitor is bigger and more costly than a ceramic capacitor with the same ESR value.
The ESR of a typical tantalum increases by approximately 2:1 as the temperature goes from 25°C down to –40°C, so some allow for guard band.