U2794B_08 Datasheet, PDF (5/15 Pages) ATMEL Corporation – 1000-MHz Quadrature Demodulator

U2794B
6. Electrical Characteristics (Continued)
Test conditions (unless otherwise specified); V_S = 5V, T_amb = 25°C, referred to test circuit
System impedance Z_O = 50Ω, f_iLO = 950 MHz, P_iLO = –10 dBm
No. Parameters
Test Conditions
Pin
Symbol
Min.
Typ. Max. Unit Type*
6 I/Q Outputs (I, IX, Q, QX) Emitter Follower I = 0.6 mA
6.1
3-dB bandwidth
w/o external C
1, 2, 19,
20
BWI/Q
≥ 30
MHz
D
6.2 I/Q amplitude error
1, 2, 19,
20
Ae
–0.5
≤ ±0.2 +0.5
dB
B
6.3 I/Q phase error
1, 2, 19,
20
Pe
–3
≤ ±1.5
+3
Deg
B
6.4
I/Q maximum output
swing
Symm. output
R_L > 5 kΩ
6.5 DC output voltage
1, 2, 19,
20
V_PP
2
D
1, 2, 19,
20
V_OUT
2.5
2.8
3.1
V
A
6.6
DC output offset
voltage
(6)
1, 2, 19,
20
V_offset
<5
mV
Test
spec.
6.7 Output impedance
see Figure 6-10
1, 2, 19,
20
Z_out
50
Ω
D
7 Gain Control, GC
Control range power
7.1 Gain high
(7)
Gain low
7.2 Switch Voltage
GCR
11
G_H
G_L
25
dB
D
23
dB
B
–2
dB
D
7.3 “Gain high”
7.4 “Gain low”
(8)
11
11 < open
1
V
7.5
Settling Time, ST
7.6
Power “OFF” - “ON”
T_SON
<4
µs
D
7.7
Power “ON” - “OFF”
T_SOFF
<4
µs
D
*) Type means: A = 100% tested, B = 100% correlation tested, C = Characterized on samples, D = Design parameter
Notes: 1. During power-down status a load circuitry with DC-isolation to GND is assumed, otherwise a current of I ≈ (VS –0.8V)/RI
has to be added to the above power-down current for each output I, IX, Q, QX.
2. The required LO-Level is a function of the LO frequency (see Figure 6-6).
3. Measured with input matching. For 950 MHz, the optional transmission line T3 at the RF input may be used for this pur-
pose. Noise figure measurements without using the differential output signal result in a worse noise figure.
4. Using pins 7 and 8 as a symmetric RF input, the second-order IIP can be improved.
5. Due to test board parasitics, this bandwidth may be reduced and not be equal for I, IX, Q, QX. If symmetry and full band-
width is required, the lowpass pins 3, 4 and 9, 10 should be isolated from the board. the bandwidth of the I/Q outputs can
be increased further by using a resistor between pins 3, 4, 9 and 10. These resistors shunt the internal loads of
RI ~ 5.4 kΩ. The decrease in gain here has to be considered.
6. The internal current of the output emitter followers is 0.6 mA. This reduces the undistorted output voltage swing at a 50Ω
load to approximately 30 mV. For low signal distortion the load impedance should be RI ≥ 5 kΩ.
7. Referred to the level of the output vector I² + Q²
8. The low-gain status is achieved with an open or high-ohmic pin 11. A recommended application circuit for switching
between high and low gain status is shown in Figure 6-1.
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4653F–CELL–11/08