MIC23156 Datasheet, PDF (16/22 Pages) Micrel Semiconductor – 1.5A, 3MHz Synchronous Buck Regulator with HyperLight Load® and I2C Control for Dynamic Voltage Scaling

Micrel, Inc.
The MIC23156 responds to a slave address of hex 0xB6
and 0xB7 for write and read operations respectively, or
binary 1011011X (where X is the read/write bit, 0 = write,
1 = read).
The register address is eight bits wide and carries the
address of the MIC23156 register to be operated upon.
Only the lower three bits are used.
MIC23156
Enable/Status Register (001b/01h)
Enable/Status register is written to enable the output
regulator (BUCK_EN) and soft start extension mode
(SSL). It is read to interrogate the status of thermal
shutdown (TSD), undervoltage lockout (UVLO), and
power good (PGOOD) status of the regulator. See Table
3 for additional information.
Buck Register 1 (010b/02h) and Buck Register 2
(011b/03h)
These registers are written to set the output voltage to
any one of 170 levels in 10mV steps. Values above
decimal 170 are equivalent to setting the register to 170.
The two registers correspond to one of two states, which
is selectable by the VSEL input pin, which allow the
regulator to be quickly switched between two voltage
levels (e.g. enabled and standby). When VSEL = 0, the
output voltage is controlled by BUCK_OUT1 (REG2).
When VSEL = 1, then the output voltage is controlled by
BUCK_OUT2 (REG3). See Table 4 and Table 5 for
additional information.
Figure 5. Required Communications for Read/Write
Operations via I²C Interface
I²C Register Summary
There are three I²C read/write registers of 8-bit length. All
registers are reset to a zero state whenever EN ≤ 0.5V
and set (reset) to their default values on the transition of
EN ≥ 1.5V. All registers are accessible by I²C.
Table 2. Register Bit Field Map
Reg.
D7
D6
D5
1
TSD
UVLO
2
BUCK_OUT1
3
BUCK_OUT2
Reg.
D3
D2
D1
1
SSL
2
BUCK_OUT1
3
BUCK_OUT2
D4
PGOOD
D0
BUCK_EN
April 22, 2013
16
Revision 1.0