Triple CRT Driver CORPORATION Preliminary Product Information CVA1405T FEATURES DESCRIPTION • • • • The CVA1405T contains three wideband amplifiers, designed specifically to drive a CRT. The device can drive monitors with resolutions up to 1024 x 768 (non-interlaced). Rise/Fall Time (at the Cathode) . . . . . . . . . . . . . . . . 9.0ns Swing . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 65VP-P Supply Voltage . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 100V Pin to Pin Compatible to CVA2404T APPLICATIONS • CRT driver for up to 64kHz monitors with resolution up to 1024 x 768 The product is housed in the industry standard 11 lead TO-220 molded power package. ORDERING INFORMATION Part Package Temperature CVA1405T T11A -20oC to +100oC CONNECTION DIAGRAM VCC 6 11 10 9 8 VIN 1 VBIAS VIN 2 VIN 3 7 6 VCC 5 4 VOUT 3 GND 3 2 1 TOP VIEW T11A PACKAGE VO 1,3,5 GND VBIAS VOUT 2 10 GND VOUT 1 VIN 11,9,8 1L-38 1T-18B 7,4,2,TAB CALOGIC CORPORATION, 237 Whitney Place, Fremont, California 94539, Telephone: 510-656-2900, FAX: 510-651-3025 CVA1405T CORPORATION ABSOLUTE MAXIMUM RATINGS Supply Voltage. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 100V Storage Temperature . . . . . . . . . . . . . . . . . . . -25oC to +125oC Operating Temperature . . . . . . . . . . . . . . . . . -20oC to +100oC Lead Temperature . . . . . . . . . . . . . . . . . . . . . . . . . . . . +300oC DC ELECTRICAL CHARACTERISTICS Vs = 80V, DCINPUT BIAS = 12V, VIN = 2.5V, TCASE = +25oC. See Figure 1. SYMBOL CHARACTERISTICS MIN TYP MAX UNITS 15 18 mA Icc Supply Current @ 1MHz VOUT DC Output DC Level 50 54 58 V Av Voltage Gain 13 15 17 V Gain Matching 0.2 dB AC ELECTRICAL CHARACTERISTICS (at the cathode) Vs = 80V, CL = 8pF, DCINPUT BIAS = 12V, VIN = 2.4V, VOUT = 50Vp-p. TCASE = +25oC. See Figure 1. SYMBOL CHARACTERISTICS MIN TYP MAX UNITS Tr Rise Time 9 11 ns Tf Fall Time 9 11 ns Le Linearity 5 % OS Overshoot/Undershoot 3 % FIGURE 1. TEST CIRCUIT VCC C3 6 VBIAS C1 D1 10 C2 CVA1405T VIN VIDEO 11,9,8 INPUT C4 VOUT 1,3,5 C6 D2 7,4,2 TEKTRONIX FET PROBE MODEL 6201 (CAP. 1.5pF) GND,TAB C1 = 0.01m F C2 = 100m F C3 = 0.1m F C4 = 100m F C6 = 8pF D1, D2 = FHD400 1T-38 CALOGIC CORPORATION, 237 Whitney Place, Fremont, California 94539, Telephone: 510-656-2900, FAX: 510-651-3025 CVA1405T CORPORATION FIGURE 2. +80V 33 W VBIAS L CVA1405T R 91 W SPARK GAP VIDEO 1T-39 FIGURE 3. +80V 1K VBIAS L CVA1405T VIDEO 33 W R C CVA4502 V cc SPARK GAP DC BIAS I.C. 1T-46 BIAS APPLICATION INFORMATION The CVA1405T is a high voltage triple CRT driver suitiable to drive 69kHz, 1024 x 768 CRT displays. It features a high impedance input to match any pre-amplifier. The CVA1405T has a true class AB output stage that results in excellent gray scale linearity and consistent EMI performance. As with any high speed amplifier used in CRT display applications, specific precaution should be taken to get the required performance. Power supply should be by pass as close to the device pin as possible. Use 0.01µf very near to the device and a large capacitor of 10µf or more (preferable 100µf) near the device. A 0.1µf and 10µf should be connected near the Vbias pin (#10). Arc protection is very essential. Fast diodes together with the spark gap will achieve sufficient protection. However, in certain applications depends on the tubes a high value of resistor is required to reduce the current into the CVA1405T during arcing. This will result in less than desireable performance some of which can be restored by using a peaking inductor at the output pin, Figure 2. Another way to achieve this is by using a RC network at the output of the device and use a peaking inductor at the tube, Figure 3. The rise and fall time of the CVA1405T may suffer due to stray capacitances associated with the PC Board and other components. It can be improved by carefully designing the PC Board where the output stage and input stage ground path are seperated. Calogic will assist customers in the layout of the PC Board that will result in quick EMI passage and better performance. The output peaking should be used only to restore the performance loss due to stray capacitances. Over peaking will cause excessive ringing that will have better results but poor EMI. The DC restore circuit is also important when considering the high frequency performance. Using CVA4502, DC Bias IC, better results can be obtained and high frequency performance can be maximixed. THERMAL CONSIDERATIONS Power supply current increases as the input signal increases and consequently power dissipation also increases. The CVA1405T cannot be used without heat sinking. The calculations below shows the power dissipated in each channel over the operating voltage range of the device. Under white screen conditions, i.e.: 25V output, dissipation increases to 8.1W total. The CVA1405T case temperature must be maintained below +100oC. If the maximum expected ambient temperature is +50oC, then a heat sink is needed with thermal resistance equal to or less than: Rth = (100 − 50oC) = 6.2oC/W 8.1W The output of CVA2405T is not short circuit proof. CALOGIC CORPORATION, 237 Whitney Place, Fremont, California 94539, Telephone: 510-656-2900, FAX: 510-651-3025 CVA1405T CORPORATION FIGURE 4. APPLICATION CIRCUIT VCC C3 VBIAS R3 6 10 C1 C2 CVA1405T VIN VIDEO 11,9,8 INPUT C4 D1 L VOUT 1,3,5 R4 C5 7,4,2 R5 SPARK GAP D2 DC BIAS GND,TAB R3 = 47W R4 = 47(1/2W)W R7 = 33W R8 = 39W R10 = 680W C1 = 0.01m F C2 = 100m F C3 = 0.1m F C4 = 100m F C5 = 2.2m F D1, D2 = FHD400 L = 330 - 390nH 1T-41 TYPICAL CHARACTERISTICS RISE TIME FALL TIME 8V 1V/DIV 1V/DIV 8V -2V -55.6ns 144.4ns 20ns/DIV -2V -55.6ns 144.4ns 20ns/DIV 1T-42 CROSS HATCH WHITE BACKGROUND 1T-43 CROSS HATCH BLACK BACKGROUND 8V 1V/DIV 1V/DIV 8V -2V -21.6ns 178.4ns 20ns/DIV 1T-45 -2V -55.6ns 144.4ns 20ns/DIV 1T-44 Information furnished by Calogic is believed to be accurate and reliable. However, no responsibility is assumed for its use: nor for any infringement of patents or other rights of third parties which may result from its use. No license is granted by implication or otherwise under any patent rights of Calogic. CALOGIC CORPORATION, 237 Whitney Place, Fremont, California 94539, Telephone: 510-656-2900, FAX: 510-651-3025