PBM3960-1 Datasheet, PDF (1/10 Pages) Ericsson – Microstepping Controller/Dual Digital-to-Analog Converter

February 1999
PBM 3960/1
Microstepping Controller/
Dual Digital-to-Analog Converter
Description
PBM 3960/1 is a dual 7-bit+sign, Digital-to-Analog Converter (DAC) especially
developed to be used together with the PBL 3771/1, Precision Stepper Motor driver
in micro-stepping applications. The circuit has a set of input registers connected to an
8-bit data port for easy interfacing directly to a microprocessor. Two registers are
used to store the data for each seven-bit DAC, the eighth bit being a sign bit (sign/
magnitude coding). A second set of registers are used for automatic fast/slow current
decay control in conjunction with the PBL 3771/1, a feature that greatly improves
high-speed micro-stepping performance. The PBM 3960/1 is fabricated in a high-
speed CMOS process.
Key Features
• Analog control voltages from 3 V
down to 0.0 V.
• High-speed microprocessor interface.
• Automatic fast/slow current decay
control.
• Full-scale error ±1 LSB.
• Interfaces directly with TTL levels and
CMOS devices.
• Fast conversion speed, 3 µs.
• Matches PBL 3771.
WR
CS
A0
A1
D7 - D0
RESET
V_DD
V_Ref
POR
DA- Data 1
E
C
D
E1
R
Level 1
E
E2
C
D
R
Level 2
E3
E
C
D
E4
R
DA- Data 2
E
C
D
R
R
Digit
Comp
E1 E
C
D
R
E4 E
Digit
Comp ^C
D
R
Vss
PBM 3960/1
Sign ₁
D/A
CD1
DA ₁
D/A
DA ₂
CD2
Sign ₂
Figure 1. Block Diagram.
PBM3960/1
396P0B/1M
22-pin plastic DIP
28-pin plastic PLCC