HMC1019LP4E
v00.0911
0.5 dB LSB GaAs MMIC 5-BIT DIGITAL
ATTENUATOR, 0.1 - 30 GHz
Serial Control Interface
The HMC1019LP4E contains a 3-wire SPI compatible digital interface (SERIN, CLK, LE). The serial control interface
is activated when S/A is kept high. The 5-bit serial word must be loaded MSB first as a 6-bit word with the first
bit ignored. The positive-edge sensitive CLK and LE requires clean transitions. If mechanical switches are used,
sufficient debouncing should be provided. When LE is high, 5-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.
For all modes of operations, the state will stay constant while LE is kept low.
Serial Mode Truth Table
Control Voltage Input
P4
8 dB
High
High
High
High
High
Low
Low
P3
4 dB
High
High
High
High
Low
High
Low
P2
2 dB
High
High
High
Low
High
High
Low
P1
1 dB
High
High
Low
High
High
High
Low
P0
0.5 dB
High
Low
High
High
High
High
Low
Attenuation
State
RF1 - RF2
Reference I.L.
0.5 dB
1 dB
2 dB
4 dB
8 dB
15.5 dB
Parameter
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
Typ.
100 ns
20 ns
20 ns
10 ns
10 ns
630 ns
10 ns
0 ns
10 ns
2 ns
Any combination of the above states will provide an attenuation
approximately equal to the sum of the bits selected.
Asynchronous Mode
The HMC1019LP4E can be switched to an asynchronous mode to change the attenuation state rapidly to one of four
predefined states. The logic state of ASM1-ASM2 determines one of the four attenuation states in the asynchronous
mode per truth table. The asynchronous mode works either directly or latched. To activate the direct-asynchronous-
mode, S/A needs to be at logic low and LE needs to be at logic high. In the direct-asynchronous-mode, any change in
the logic state of ASM1-ASM2 directly affects the attenuation state. In the latched-asynchronous-mode, the attenuation
state changes per the asynchronous mode truth table when S/A is at logic low and LE is pulsed per the timing diagram.
The attenuation stays constant (latched) as long as LE stays low. In the asynchronous mode, the inputs SERIN and
CLK do not affect the attenuation state.
For price, delivery and to place orders: Hittite Microwave Corporation, 2 Elizabeth Drive, Chelmsford, MA 01824
Phone: 978-250-3343
Fax: 978-250-3373
Order On-line at www.hittite.com
Application Support: Phone: 978-250-3343 or apps@hittite.com
AttenuAtors - DigitAl - sMt
4
HITTITE [ HITTITE MICROWAVE CORPORATION ]
