HMC742LP5_09 Datasheet, PDF (6/12 Pages) Hittite Microwave Corporation – 0.5 dB LSB GaAs MMIC 6-BIT DIGITAL VARIABLE GAIN AMPLIFIER, 70 MHz - 4 GHz

HMC742LP5E
v03.0709
0.5 dB LSB GaAs MMIC 6-BIT DIGITAL
VARIABLE GAIN AMPLIFIER, 70 MHz - 4 GHz
Serial Control Interface
The HMC742LP5E contains a 3-wire SPI compatible digital interface (SERIN, CLK, LE). The serial control interrface is
activated when P/S is kept high. The 6-bit serial word must be loaded MSB first. The positive-edge sensitive CLK and
LE requires clean transitions. If mechanical switches are used, sufficient debouncing should be provided. When LE is
high, 6-bit data in the serial input register is transferred to the attenuator. When LE is high CLK is masked to prevent
data transition during output loading.
When P/S is low, 3-wire SPI interface inputs (SERIN, CLK, LE) are disabled and the input register is loaded with
parallel digital inputs (D0-D5). When LE is high, 6-bit parallel data changes the state of the part per truth table.
For all modes of operations, the DVGA state will stay constant while LE is kept low.
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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
Hold Time, t
PH.
Latch Enable Minimum Width, t
LEN
Setup Time, t
PS
100 ns
20 ns
20 ns
10 ns
10 ns
630 ns
10 ns
0 ns
10 ns
2 ns
Timing Diagram (Latched Parallel Mode)
Parallel Mode
(Direct Parallel Mode & Latched Parallel Mode)
Note: The parallel mode is enabled when P/S is set to low.
Direct Parallel Mode - The attenuation state is changed by the control voltage inputs D0-D5 directly. The LE (Latch
Enable) must be at a logic high at all times to control the attenuator in this manner.
Latched Parallel Mode - The attenuation state is selected using the control voltage inputs D0-D5 and set while the
LE is in the Low state. The attenuator will not change state while LE is Low. Once all Control Voltage Inputs are at the
desired states the LE is pulsed. See timing diagram above for reference.
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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