仪表放大器INA128的管脚REF是否可以连电压基准

仪表放大器INA128的输出是相对于管脚REF的电压来说的.即 Vout = Gain*（Vin+ - Vin-）+REF.
REF接电压基准的目的是提高输出的电位。
产品手册上说，一般REF接地，而且要低阻抗相连。
“The output is referred to the output reference (Ref)terminal which is normally grounded. This must be a
low-impedance connection to assure good common-mode rejection. A resistance of 8
Ω in series with the Ref pin will cause a typical device to degrade to approximately 80dB CMR”

下图是一个REF不接地的例子。

运放保证了低阻抗连接。"The op amp buffer provides low impedance at the Ref terminal to preserve good common-mode rejection." 

运放保证了低阻抗连接，是不是因为运放的输出电阻比较小？如果我要在INA128的REF管脚接2V的电压基准，是不是也不能直接连接，需要加一个运放？