A4979
Microstepping Programmable Stepper Motor Driver
With Stall Detect and Short Circuit Protection
ELECTRICAL CHARACTERISTICS1,2 (continued) Valid at TA = 25°C, VBB = 50 V, VDD = 3.3 V; unless otherwise noted
Characteristics
Symbol
Test Conditions
Min.
Typ.
Max.
Unit
Logic Input And Output – Dynamic Parameters (continued)
Setup Time Control Input Change
to STEP
tSU
MS1, MS2, DIR
200
–
–
ns
Hold Time Control Input Change
from STEP
tH
MS1, MS2, DIR
200
–
–
ns
Wake-Up from RESET
tEN
Diagnostics and Protection
–
–
1
ms
VREG Undervoltage Threshold
VREGUV VREG falling
5.1
–
5.4
V
VREG Undervoltage Hysteresis
VRGUVHys
–
1
–
V
VDD Undervoltage Threshold
VDDUV VDD falling
2.6
–
2.9
V
VDD Undervoltage Hysteresis
VDDUVHys
50
100
–
mV
OSC Timeout
tWD
Bit 13 = 1
0.5
1
1.5
μs
High-Side Overcurrent Threshold
IOCH
Sampled after tSCT
1.7
2.05
2.95
A
High-Side Current Limit
ILIMH Active during tSCT
3
5.5
8
A
Low-Side Overcurrent Sense Voltage
VOCL Sampled after tSCT
210
250
290
mV
Overcurrent Fault Delay
tSCT Default Fault Delay
1500
2000
2700
ns
Open Load Current Threshold Error
EIOC VREF = 2 V, Mx0 = Mx1 = 1
–
–
±10
%
Temperature Voltage Output Offset
VTO Temperature output selected on DIAG pin
–
1440
–
mV
Temperature Voltage Output Slope
AT
–
–3.92
–
mV/°C
Cold Temperature Warning Threshold
TJWC Temperature decreasing
–20
–10
0
ºC
Cold Temperature Warning Hysteresis TJWChys
–
15
–
ºC
Hot Temperature Warning Threshold
TJWH Temperature increasing
125
135
145
ºC
Hot Temperature Warning Hysteresis TJWHhys
–
15
–
ºC
Overtemperature Shutdown Threshold
TJF
Temperature increasing
155
170
–
ºC
Overtemperature Hysteresis
TJhys Recovery = TJF – TJhys
–
15
–
ºC
1For input and output current specifications, negative current is defined as coming out of (sourcing) the specified device pin.
2All references to “VBB” apply to VBBA and VBBB.
3Assumes a 4 MHz clock.
4Current Trip Point Error is the difference between actual current trip point and the target current trip point, referred to maximum full scale (100%)
current: EItrip = 100 × [ItripActual – ItripTarget ] / IFullScale (%).
Allegro MicroSystems, LLC
7
115 Northeast Cutoff
Worcester, Massachusetts 01615-0036 U.S.A.
1.508.853.5000; www.allegromicro.com