6

65, 66,

67, 68,

69, 70,

71, 72,

73

GND

Ground. Connect to a solid ground plane.

74

LIM1_PE

Digital input control to enable the limiter amplifier 1. Enable logic level is High.

75

Limiter amplifier 1 supply pin. Use high quality decoupling capacitors right at the pin.

76

LIM1_Out-

Negative output of limiter amplifier 1. Requires AC coupling.

77

LIM1_Out+

Positive output of limiter amplifier 1. Requires AC coupling.

78

GND

Ground. Connect to a solid ground plane.

79

RSSI_RL1

Load resistor to ground. Nominal value is 6k

Ω. This load is used to terminate the LIM RSSI current output and

maintain temperature and process variation to a minimum.

80

LIM1_RSSI

Current output of RSSI for the limiter amplifier 1. Connect in parallel with the RSSI output of the amplifier limiter 2

for cascaded response.

NOTES:

1. The HFA3726 generates a lower side band signal when the “I” input leads the “Q” input by 90 degrees.

2. For a reference LO frequency higher than a CW IF signal input, the “I” channel leads the “Q” channel by 90 degrees.

3. The in-phase reference LO transitions occur at the rising edges of the 2XLO signal. Quadrature LO transitions occur at the falling edges. 180

degrees phase ambiguity is expected for carrier locked systems without differential encoding.

TABLE 1. POWER MANAGEMENT

TRANSMIT

RECEIVE

POWER DOWN

LIM1_PE

0

1

0

LIM2_PE

0

1

0

LPF_RX_PE

0

1

0

MOD_RX_PE

0

1

0

MOD_TX_PE

1

0

0

LPF_TX_PE

1

0

0

PIN

SYMBOL

DESCRIPTION

HFA3726