LUCL7590CAE-DT

Data Sheet June 1998 L7590C Telephone Ringing Driver Features s Description The L7590C Telephone Ringing Driver produces a low-frequency sinusoidal ringing signal for analog telephone loops. This is accomplished by producing an output pulse stream that is an amplified replica of the digital input. The output is then filtered to produce a sine wave. The peak-to-peak output level is determined by the magnitude of the negative high-voltage dc applied to the device (up to –170 V). The required input is a 100 kHz CMOS-compatible pulse stream, pulse-width modulated (PWM) at the desired ringing frequency. The output stage consists of one upper and one lower drive transistor with an internal control circuit. The L7590C IC is optimized for low power dissipation and is available in a 16-pin, surface-mount package. Applies a battery-backed, single-ended, sinusoidal ringing signal to the telephone loop Ringing capability: — 40 Vrms into 5 North American REN — 30 mApeak into 4 German REN Built-in current limiting Low power dissipation in idle and ringing modes Requires 5 V, a high-value negative dc supply, and a digital input sequence s s s s GNDD VDD GNDR CB1 CB2 OUT CURRENT LIMIT EN CLOCK CONTROL CLK LEVEL SHIFT AND OUTPUT TIMING L2 30 Ω L1 BIAS CIRCUIT VNEG VREF VNEG 12-3057a (f) Figure 1. Block Diagram L7590C Telephone Ringing Driver Data Sheet June 1998 Pin Information Pin 14 3 12 8 5 16 7 1 2 9 10 15 Symbol VDD GNDD GNDR VNEG VREF CLK OUT CB1 CB2 L1 L2 EN Type — — —...