BA8201

Communication ICs Pseudo inductance for telephones BA8201 / BA8201F The BA8201 and BA8201F are ICs with a choke coil action, capable of extracting the DC current from a telephone line while maintaining a high inductance on the telephone line side. This eliminates the need for a choke coil, and facilitates use of the telephone set line in a variety of applications. FApplications Household telephones FFeatures 1) Corresponds to choke coil of several henries. 2) Extracts DC current while maintaining high inductance on telephone line side. 3) Capable of extracting large output current. 4) Wide dynamic range. 5) Two output voltage modes available for selection. S Line voltage seek mode S Constant voltage mode 6) DIP 8 and SOP 8 pin packages available. FAbsolute maximum ratings (Ta = 25_C) FRecommended operating conditions (Ta = 25_C) 300 Communication ICs FBlock diagram BA8201 / BA8201F 301 Communication ICs FPin descriptions BA8201 / BA8201F 302 Communication ICs BA8201 / BA8201F FElectrical characteristics (unless otherwise noted, Ta = 25_C, VLN = 4V, υLN = 100mVrms, Io = 5mA, f = 1kHz) FMeasurement circuits 303 Communication ICs BA8201 / BA8201F 304 Communication ICs FApplication example BA8201 / BA8201F FAttached components C1: This is a capacitor for phase compensation, and is normally connected at 68pF. C2: This is a coupling capacitor. The inductance from the telephone line changes based on this value. Normally, a value of 2.2µF to 10µF is appropriate. C3: This is a capacitor for phase compensation, and is normally connected at 47pF. C4: This is the capacitor for balancing the output. It suppresses rippling in the output and also carries out decoupling for the bias voltage supply of the IF pin. It should be adjusted based on the output current, load, and other factors. R1: Bias is applied from this pin to the IF pin. The inductance from the telephone line changes based on this value. Normally, a value of 100kΩ is appropriate. R2: This can be connected between Pins 6 and 7 to clamp the output voltage. The output voltage is expressed using the equation below. Vo (V) = 2 22 (µA) R2 (Ω) (reference value) ∗22µA is the reference internal current source for the IC. 305 Communication ICs FElectrical characteristic curves BA8201 / BA8201F 306 Communication ICs FExternal dimensions (Units: mm) BA8201 / BA8201F 307