ISL59834 Datasheet, PDF (13/17 Pages) Intersil Corporation – Quad Channel, Single Supply, Video Reconstruction Filter with On-Board Charge Pump

ISL59834
Typical Performance Curves V_CP = V_S = 3.3V, C_F1 = C_F2 = 0.1µF, C_S1 = C_S2 = 0.22µF, C_FIL1 = C_FIL2 = 0.4µF, C_IN1 = C_IN2 =
C_IN3 = C_IN4 = 0.1µF, R_L1 = R_L2 = 150Ω. (Continued)
100
RMS NOISE = 2.87mV
OUTPUT REFERRED
TIME SCALE = 50ns/DIV
VERTICAL SCALE = 20mV/DIV
10
CHARGE PUMP NOISE,
CONTRIBUTES ONLY A SMALL
PERCENTAGE OF THE
OVERALL NOISE
1
0.1
0M
1M 2M 3M 4M 5M 6M 7M 8M
FREQUENCY (Hz)
FIGURE 25. NOISE SPECTRUM
9M 10M
0
V_S = V_CP = +3.3V
-10 _{RL = 150Ω}
-20 ^{VOUT = 0 TO 2VP, SINE WAVE}
-30
-40
-50
f_IN = 500kHz
f_IN = 5MHz
-60
-70
0.5
0.8
1.1
1.4
1.7
2.0
OUTPUT VOLTAGE (V)
FIGURE 27. THD (dBc) vs OUTPUT VOLTAGE (V_P-P)
FIGURE 26. CHARGE PUMP FEEDTHROUGH AT AMPLIFIER
OUTPUT
4.5
4.0
3.5
3.0
2.5
44 LD QFN PACKAGE
2.0
7mmx7mm
1.5
θ_JA = +32°C/W
1.0
0.5
0
0 5 10 15 20 25 30 35 40 45 50 55 60 65 70 75 80 85 90
AMBIENT TEMPERATURE (°C)
FIGURE 28. PACKAGE POWER DISSIPATION
Description of Operation and Application Information
Theory of Operation
The ISL59834 is a single supply video driver with a
reconstruction filter and an on-board charge pump. It is
designed to drive SDTV displays with component (YPbPr),
S-video (Y-C), or composite video (CV) signals. The input
signals can be AC or DC-coupled. When AC-coupled, a sync
tip clamp sets the blank level to ground at the output of
Channel 1 and Channel 3. Keyed clamps force the average
levels of Channel 2 and Channel 4 to ground. The keyed
clamps force the outputs to ground when SYNC_INA or
SYNC_INB are driven to the logic high state. The ISL59834
outputs are capable of driving two AC or DC-coupled
standard video loads and have a 4^th order Butterworth
reconstruction filter with nominal -3dB frequency set to
9MHz, providing 40dB of attenuation at 27MHz. The
ISL59834 is designed to operate with a single supply voltage
range ranging from 3.0V to 3.6V. This eliminates the need for
a split supply with the incorporation of two charge pumps
capable of generating a bottom rail as much as 1.5V below
ground; providing a 4.8V range on a single 3.3V supply. This
performance is ideal for NTSC video with negative-going
sync pulses.
Output Amplifier
The ISL59834 output amplifiers provide a gain of +6dB. The
output amplifiers are able to drive a 2.8V_P-P video signal into
a 150Ω or 75Ω load to ground.
The outputs are highly-stable, low distortion, low power, high
frequency amplifiers capable of driving moderate (~10pF)
capacitive loads.
Input/Output Range
The ISL59834 has a dynamic input range of 0 to 1.4V_P-P
This allows the device to handle high amplitude video signal
inputs. As the input signal moves outside the specified
range, the output signal will exhibit increasingly higher levels
of harmonic distortion.
Charge Pump
The ISL59834 contains two charge pumps; charge pump A
supplies Channel 1 and 2, while charge pump B supplies
Channel 3 and 4. The ISL59834 charge pumps provide a
bottom rail up to 1.5V below ground while operating on a
3.0V to 3.6V power supply. The charge pumps are internally
regulated and are driven by internal 9.5MHz clocks. The
13
FN6268.1
June 11, 2008