Starpoint Adaptive Optics

Data Sheet

AmpArrayLV

Overview

The AmpArrayLV™ is a low voltage, high current, 37-channel amplifier unit capable of driving adaptive mirrors with actuator load capacitances in the 1μF – 10μF range, at the frequencies typically required to correct atmospheric turbulence. It contains no internal digital-to-analogue converters, and is intended to be driven by an external source of analogue control signals.

Each amplifier channel delivers a ±20V swing about a −40V or −60V bias level, providing 2.6μm of stroke for mirrors with a 0.07μm/V actuator response. The 5mA mean drive current is sufficient to drive a 10μF actuator at atmospheric turbulence frequencies. The AmpArrayLV provides hardware voltage limiting between nearest neighbour actuators, a safety feature required by many continuous face-sheet mirrors. The quiescent power dissipation is exceptionally low.

The analogue in–analogue out interface configuration was created to allow a deformable mirror to be controlled directly from high-level data acquisition and instrument control software, without requiring additional device driver software. The AmpArrayLV would typically be driven by a PC multi-channel DAC card supported by the user's preferred high-level software. The input specification matches the output characteristics of many popular DAC cards offered with the leading instrument control software packages.

This simple yet versatile device comes in a compact enclosure and requires only a single +5V dc power supply input. It is priced at less than £40 per channel. It offers a convenient and economical way to control continuous face-sheet mirrors that have high actuator capacitance.

System Specification

	System Characteristics
	Number of amplifier channels	37
	Amplifier Gain	−2.1± 2%
	Input Characteristics
	Input Voltage Range	−10V to +10V
	Input Impedance	150kΩ
	Output Characteristics
	Output Voltage Range	−20V to +20V
	Bias Voltage	−40V or −60V, manually settable.
	Nearest Neighbour Voltage Limit	20.0V ≤ \|ΔV\| ≤ 22.1V
	Output Drive Current (mean)	5mA
	Signal Bandwidth	500Hz @ -3dB corner
	Physical Characteristics
	Quiescent Power Dissipation	35mW / channel
	Enclosure Dimensions	166mm(D) × 106mm(W) × 34mm(H)
	Power In	+5V dc regulated, @ 2A

Connector Pin Assignment

	System Connectors:
	Signal Input Connector:	44-way HD22 (density-and-a-half) 'D'-type socket.
	Drive Output Connector:	78-way HD22 (density-and-a-half) 'D'-type socket.
	Power Supply Connector:	0.1" pin miniature power jack. (Power supply is included).

Pin assignment on the input (44-way) and output (78-way) 'D'-type connectors, and the protection diode configuration. The diode array imposes a fixed mapping of amplifier channels onto mirror actuators. This mapping must be adhered to.


Input Connector: 44-way		Output Connector: 78-way

Pin No.	Signal	Pin No.	Signal	Pin No.	Signal
1	IN36	1	OUT0	40	OUT1
2	GND	2	OUT2	41	OUT3
3	IN31	3	OUT4	42	OUT5
4	GND	4	OUT6	43	OUT7
5	IN26	5	OUT8	44	OUT9
6	IN23	6	OUT10	45	OUT11
7	IN21	7	OUT12	46	OUT13
8	IN18	8	OUT14	47	OUT15
9	IN15	9	OUT16	48	OUT17
10	IN13	10	OUT18	49	GND
11	IN10	11	OUT19	50	OUT20
12	GND	12	OUT21	51	OUT22
13	IN5	13	OUT23	52	OUT24
14	GND	14	OUT25	53	OUT26
15	IN0	15	OUT27	54	OUT28
16	GND	16	OUT29	55	OUT30
17	IN34	17	OUT31	56	OUT32
18	IN32	18	OUT33	57	OUT34
19	IN29	19	OUT35	58	OUT36
20	IN27	20	GND	59	GND
21	IN24	21	BIAS	60	BIAS
22	GND	22	BIAS	61	BIAS
23	IN19	23	BIAS	62	BIAS
24	IN16	24	BIAS	63	BIAS
25	IN14	25	BIAS	64	BIAS
26	IN11	26	BIAS	65	BIAS
27	IN8	27	BIAS	66	BIAS
28	IN6	28	BIAS	67	BIAS
29	IN3	29	BIAS	68	BIAS
30	IN1	30	BIAS	69	GND
31	IN35	31	BIAS	70	BIAS
32	IN33	32	BIAS	71	BIAS
33	IN30	33	BIAS	72	BIAS
34	IN28	34	BIAS	73	BIAS
35	IN25	35	BIAS	74	BIAS
36	IN22	36	BIAS	75	BIAS
37	IN20	37	BIAS	76	BIAS
38	IN17	38	BIAS	77	BIAS
39	GND	39	BIAS	78	BIAS
40	IN12
41	IN9
42	IN7
43	IN4
44	IN2