HMC743LP6C Datasheet, PDF (10/14 Pages) Hittite Microwave Corporation – 0.5 dB LSB GaAs MMIC 12-BIT DIGITAL VARIABLE GAIN AMPLIFIER, DC - 4 GHz

v02.0709
HMC743LP6C / 743LP6CE
0.5 dB LSB GaAs MMIC 12-BIT DIGITAL
VARIABLE GAIN AMPLIFIER, DC - 4 GHz
Serial Control Interface
The HMC743LP6C(E) contains a 3-wire SPI compatible digital interface (SERIN, CLK, LEA (or LEB)) that is used to
control the input and output gain control elements (digital attenuators). The input (IN) and output (OUT) attenuators
can be individually controlled thru the latch enable pins. The LEA pin latches the serial 6-bit control word to the output
attenuator. The LEB pin latches the serial 6-bit control word to the input attenuator.
The 6-bit serial word can be loaded either MSB first or LSB first depending on the state of the BO (bit order) pin.
Setting BO to high configures the serial controller to operate in LSB first mode. Setting BO to low configures the serial
controller to operate in MSB first mode.
When LEA or LEB (or both) is raised to a logic high, 6-bit data in the serial input register is transferred to the input
attenuator or the output attenuator (or both). While either LEA or LEB are high, CLK signal must be masked or stopped
to prevent data transition during output loading.
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Timing Diagram
Timing diagram is used for either input or output digital
gain control. Control word is shown with MSB first (BO
= Low) configuration.
Parameter
Typ.
Min. serial period, t
SCK
Control set-up time, t
CS
Control hold-time, t
CH
LE setup-time, t
LN
Min. LE pulse width, t
LEW
Min LE pulse spacing, t
LES
Serial clock hold-time from LE, t
CKN
100 ns
20 ns
20 ns
10 ns
10 ns
630 ns
10 ns
PUP Truth Table
LE
(A and B)
PUP1
PUP2 Gain Relative to Max Setting
0
0
0
-63 dB
0
1
1
0 dB
Power-Up States
The HMC743LP6C offers two different power up
states, either full attenuation or maximum gain mode.
See truth table.
Power-On Sequence
The ideal power-up sequence is: GND, Vdd, digital
inputs, RF inputs. The relative order of the digital
inputs are not important as long as they are powered
after Vdd / GND
For price, delivery, and to place orders, please contact Hittite Microwave Corporation:
20 Alpha Road, Chelmsford, MA 01824 Phone: [phone] Fax: [phone]
Order On-line at www.hittite.com
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