QUICK REFERENCE DATA
VP supply voltage
Iq quiescent supply current
IO(p-p) output current
Idiff(p-p) differential input current (peak-to-peak value)
Vdiff(p-p) differential input voltage (peak-to-peak value)
IM peak output current
VFB flyback supply voltage
Tstg storage temperature
Tamb operating ambient temperature
Tvj virtual junction temperature
The vertical driver circuit is a bridge configuration. The deflection coil is connected between the output
amplifiers, which are driven in phase opposition. An external resistor (RM) connected in series with the
deflection coil provides internal feedback information. The differential input circuit is voltage driven. An
external resistor (RCON) connected between the differential input determines the output current
through the deflection coil. The relationship between the differential input current and
the output current is defined by: Idiff xRCON = Icoil xRM.The output current is adjustable from 0.5 A (p-p)
to 2 A (p-p) by varying RM. The maximum input differential voltage is 1.8 V. In the application it is
recommended that Vdiff = 1.5 V (typ). This is recommended because of the spread of input current and
the spread in the value of RCON. The flyback voltage is determined by an additional supply voltage VFB.
The principle of operating with two supply voltages (class G) makes it possible to fix the supply
voltage VP optimum for the scan voltage and the second supply voltage VFB optimum for the flyback
voltage. Using this method, very high efficiency is achieved.
The supply voltage VFB is almost totally available as flyback voltage across the coil, this being
possible due to the absence of a decoupling capacitor (not necessary, due to the bridge configuration).
The output circuit is fully protected against the following:
• thermal protection
• short-circuit protection of the output pins (pins 4 and 7)
• short-circuit of the output pins to VP.
A guard circuit VO(guard) is provided. The guard circuit is activated at the following conditions:
• during flyback
• during short-circuit of the coil and during short-circuit of the output pins (pins 4 and 7) to VP or
• during open loop
• when the thermal protection is activated.
This signal can be used for blanking the picture tube screen.